That is very exceptional. I've written fuel estimation software for airliners (cargo, fortunately), and the number of rules regarding go-arounds, alternates and holding time resulted in there usually being quite a bit of fuel in the tanks on landing, by design. I've never heard of '6 minutes left' in practice where it wasn't a massive issue and the investigation into how this could have happened will make for interesting reading. A couple of notes: the wind and the time spent on the three go-arounds + what was necessary to get to the alternate may not be the whole story here, that's actually factored in before you even take off.
I'd be very wary to get ahead of the investigation and make speculative statements on how this could have happened, the one thing that I know for sure is that it shouldn't have happened, no matter what.
Naively as an outsider, this situation seems like everything worked as intended?
On a nominally 2h45m flight, they spent an extra 2 hours in the air, presumably doing doing fuel intensive altitude changing maneuvers, and were eventually able to land safely with their reserves almost exhausted.
I’m a little confused by what there is to investigate at all.
As others have said, final fuel reserves are typically at least half an hour, and you shouldn't really be cutting into them. What if their first approach into MAN had led to another go around?
With a major storm heading north-easterly across the UK, the planning should have reasonably foreseen that an airport 56 miles east may also be unavailable, and should've further diverted prior to that point.
They likely used the majority of their final fuel reserve on the secondary diversion from EDI to MAN, presumably having planned to land at their alternate (EDI) around the time they reached the final fuel reserve.
Any CAA report into this, if there is one produced, is going to be interesting, because there's multiple people having made multiple decisions that led to this.
Suspect they were IFR. All your points stand. First time flying things with a jet engine, I was shocked how much more fuel gets burned at low altitude. It almost always works out better to max climb to altitude and descend than to fly low and level. On a small jet, things can get spicy fast when ATC route you around at 5000' for 15 minutes or so. Three aborted landings would gobble gas like crazy.
§ 91.167 Fuel requirements for flight in IFR conditions.
(a) No person may operate a civil aircraft in IFR conditions unless it carries enough fuel (considering weather reports and forecasts and weather conditions) to—
(1) Complete the flight to the first airport of intended landing;
(2) Except as provided in paragraph (b) of this section, fly from that airport to the alternate airport; and
(3) Fly after that for 45 minutes at normal cruising speed
Just reaching altitude again to make it to the first and later second alternate are mostly likely the biggest factors in the extra fuel consumption. That's very expensive.
The 30 min reserve is on top of the fuel needed to reach the alternate and do a landing there, so only the flight to the second alternate, plus the 2nd and 3rd landings at the initial destination would have cut into the reserve.
With 100mph winds I could easily see the 30 min reserve being eaten up by the flight from Edinburgh to Manchester. It's 178 miles! It takes a good 15-20 minutes to cross that distance when flying normally, add ascent & descent time and the landing pattern and you're easily at 24 minutes.
Edit: in other comments here, it seems like Edinburgh to Manchester is a 45 minute flight. So yeah, they could easily have been outside of reserves when they did the go-around at Edinburgh and still had only 6 minutes left at Manchester.
Yeah, although it depends what the alternate was in the flight plan. It may have been Manchester. Although I think its more likely it was Edinburgh, which in the circumstances was too optimistic. Too much concern about the minimal costs of fuel tankering to add a bit more gas? Or saving time by not refuelling?
Yes, you get "some" back, and its not negligible amount. Typical modern airliner can descend on 15-20:1, giving you over 150-200km (90-120mi) range from typical cruising altitude of 33 000 feet even with engines off. Most everyday descents are actually done by maintaining altitude as long as possible, and then iddling the engines fully for as long as clearance allows. (Ofc you then use engines as you geat nearer, because its safer to be a little low when stabilizing on approach, than a little high)
Thanks to turbofans(edited from turboprops) better efficiency + less drag at higher altitude its actually more fuel economical to command full thrust and gain altitude quickly, than slower climb, or maintaining altitude (which goes against our intuition from cars, where if you wanna get far, you never give full throttle).
But theres still some drag, so you dont get everything back, so you generally want to avoid murking in low altitudes as long as possible. Full thrust repeatedly at lowest altitudes (from failed go arounds) is the least economical part of flight, so you want to avoid those if possible. But its true that the altitude you gain is equivalent to "banking" the energy, just not all of it.
Edit: changed turbofan into turbprop, which is what I meant.
(2) fuel burned stays burned, you don't 'get it back'
(3) the altitude gained may have been adjusted to account for the low fuel situation
(4) the winds are a major factor here, far larger than the fact that 'what goes up must come down', something that is already taken into account when computing the fuel reserve in the first place.
> fuel burned stays burned, you don't 'get it back'
The it that they get back is not fuel, it's energy. Maintaining flight is energy management. They are getting the gravitational potential energy back, which is converted to velocity on descent, or bled off in drag by slowly losing altitude while maintaining airspeed.
(1) The turbofan category of jet engine seems to inspire a lot of very pretty animated technical diagrams—here’s one set from a German manufacturer [0]. Now if only we could convince Bartozs Ciechanowski to take on such a subject… [1]
(2) I know glider pilots who fly without any fuel at all, once aloft… sounds not unlike the 150-200km glide range that @MaxikCZ mentions at idle from cruising altitude.
Aircraft that are designed as gliders are much lighter and thus have much longer glide range than aircraft that aren't. They're so lightweight that they can climb on thermals. A 737 is not going to be able to do that, but a regular glider can't fly at 400 knots.
Im gonna be a little pedantic, but the weight has surprisingly small effect on glide range, actually none of the weight affect the range directly, its all from secondary effects.
The glide is given mainly by drag and lift (so body and wing geometry), correlated to certain speed. The weight isnt in the equation at all. What weight does, is increases the speed in which the aircraft achieves this maximum glide ratio, and in higher speed you have higher drag, which finally reduces the range.
Thats why many modern gliders have water tanks in wings, to increase the weight of the glider, moving planes speed of best glide ratio higher, allowing for more efficiency at higher speeds. Its worth it if the atmospheric condition provide strong lifts. Pilot can then dump the water in flight to reduce the wing load, allowing them to land with less speed, or just keep in the air longer as thermals get weaker in the afternoon/evening
It should also be noted that gliders have crazy aspect ratios. Airliner wings are designed for completely different flight envelopes than gliders, it’s all a game of what you optimize for and what trade offs you are willing and/or required to make.
But of course that doesn’t mean that airliners can’t glide well, the Gimly Glider and Air Transat flight come to mind. But gliders can definitely beat an airliner in terms of performance.
Regarding the turbofan and [0], above...if you're communicating to a non-engineer (me), how does the design get to the point of such complexity? I would love to learn the design story behind such an incredibly complex piece of machinery.
Re: (2): There's a difference between sailplanes and gliders. Sailplanes are gliders that can “soar”, i.e. gain altitude just from the air that is moving up for some reason. Your friends have licence that says „Sailplane Pilot Licence”, not „Glider”.
The distinction is less pronounced nowadays, because there is no mondern aircraft designed as gliders-but-not-sailplanes, but historically there were planes that fit this niche, mostly military transport of WW1 and WW2 vintage.
Passenger jets (with engines turned off) are relatively decent gliders, but incapable of soaring. So no, you can't get more that about 20:1 glide ratio no matter how good is the weather (for sailplanes).
No, you don’t magically get the fuel back. But you do get a lot of the _kinetic energy_ back, and that energy keeps you flying without having to burn yet more fuel. You burn a lot of fuel while climbing, but then hardly any at all while descending. And that descent might cover 100 miles across the ground.
2) It stays burned, but the energy is banked in potential energy of the aircraft, namely in a form of altitude. If you run out of fuel 5 feet above ground, you dont get to fly far. When you run out of fuel 35000 feet above ground, you can still choose where to land from multiple options.
3) huh? I dont get what you trying to say, but: Its always more economical to climb, and the faster the better. Ofc you cant climb too high when you intend to attempt to land in 5-10 mins, but nontheless, every feet gained is "banked", and the aircraft is more economical to run the higher you are.
4) I am not saying the winds arent a factor, and in no way I was arguing about how fuel reserves are calculated. My only claim is that: yes, by spending more fuel to gain altitude, you can then "glide" down almost for free later. Its not 1:1, because of constant losses like drag, but its being compensated by higher engine efficiency and less drag at altitude, that its always worth it to climb if you can.
There was a flight that was low on fuel diverting to alternate between 2 islands. The pilot panicked and chose slower climb to intuitively save fuel. They had to ditch the plane in water because of it - if they initiated full climb, they would have made the jump.
1 - a turbofan is a subset of jet engine, and there are no 738s running anything other than a turbofan.
Actually, nothing in civil aviation that has a "jet engine" has used anything but a turbofan (or turboprop) since the early 70s with the exception of Concorde and some older business jets.
(Turboprops are jet engines, too, to be precise, with the jet of exhaust gases powering the propeller.)
They are certainly turbine engines, but I thought "jet" was reserved for those engines that propel the vehicle solely by their exhaust stream and bypass air. I am willing to be told I'm wrong, though.
Yes, you get a lot of the energy back, BUT there is a huge problem!
Large airliners incur a LOT of additional drag to slow down while landing. Some of that is entirely intentional, some is less intentional.
It is highly preferred to deploy the landing gear before touching down. Failure to do so may lead to a hard landing and additional paperwork, so airlines do not allow the captain to exercise their own discretion.
Extending the flaps maintains lift at lower speed, and higher flap settings allow even lower speed. The highest flap setting generally also deploys leading edge slats.
If the wheels of the airliner touch down and detect the weight of the plane then spoilers kill the lift of the wings, air brakes fully deploy, as well as thrust reversers.
All of these things add drag, which uses up all that energy you've been converting.
The upshot is that each landing attempt uses a LOT of energy, and you have to use fuel to replenish that energy after every attempt.
In other words, yes you get it back, but only for one landing attempt.
That is perplexing. Of course you get the potential energy back. It turns into kinetic energy as you descend. That is why you need not pedal downhill, and often even need to brake to prevent the bike from speeding up too dangerously.
> often even need to brake to prevent the bike from speeding up too dangerously.
Indeed, which is what the airplane would have done on its way down to land. So it's more like riding the brakes on your way down the hill, and now at the bottom when you realize you need to abort the landing, you are at low speed and it's quite an exercise to get back uphill to try again
100%. You are correct on that. You can’t use your kinetic energy to go around after a landing attempt.
But not because “you don’t get the energy back”. (As recursive suggested about a downhill bike ride which is the part i am disagreeing with.) You do get it back, but because you want to land you bleed it away to drag. And once it is bled away you don’t have it anymore.
So we don’t disagree about the practical implications for flying. I’m disagreeing with recursive’s particular statement about downhill cycling and what it implies about the physics of the problem.
The glider guys would always suggest a forward slip. It's a lot of fun to do. It's not taught often enough during primary training for powered airplanes.
Imagine a hill with 500 feet of elevation descent, followed immediately by 500 feet of ascent. No curves.
If you coast all the way down the first part, you'll get about 20 feet up the other hill before you need to start pedaling. This is a direct analogy to "getting your energy back" by losing elevation.
That is exactly what a rollercoaster does and it doesn’t start “pedaling” after 20 feet. Of course real systems have losses and you can’t practically use all the energy.
It is a glider so it can’t “pedal”. You can see it steeply descending from 5:13 to 5:30 while it is speeding up and then the pilot picks up the nose and trades some of his speed for elevation again. And then he does it again around the 7 minutes mark.
You have two buckets of “water”. One bucket is kinetic energy and the other is potential energy. You can trade one for the other. You can also “lose” from the total volume of “water” due to drag (or friction in the case of the bike or roller coaster). Or you can add more “water” to your system by pedaling or thrusting with your engines. This is just simple physics 101. Also simple lived experience if you ever have the opportunity to fly an airplane.
Just as with bikes, it will depend on how slow it is descending. On "right" trajectory engines could technically be basically idle, and you save fuel flying high so it might not be all that huge loss.
How? On descent you can trade some of your altitude (potential energy) for kinetic energy, but then you can’t land the plane. For descent on an approach you’re going from low energy to even lower energy. In emergencies and with enough runway you can futz around with this some, but wiggle room on an airliner is not great, negligible to what will be expended on a go around.
Not really. While you have a large potential energy buildup at a higher altitude, you cannot "bank it" / "save it" on descent. There is no way to store it in batteries or convert it back into fuel.
One of the challenges of aeronautics is the efficient disposition of the potential energy without converting it all into kinetic energy (ie speed) so that the landing happens at an optimally low speed - thus giving you a chance to brake and slow down at the end.
Some of it. The air density is an important part of efficiency at higher altitudes, so every moment spent under like FL320 is wasted fuel.
So the entire climb "up", you are also wasting energy fighting the thick air. On the way back "down", that air again fights you, even though you are basically at idle thrust.
Your fuel reserves are calculated for cruise flight, so time spent doing low altitude flying is already at a disadvantage. "Two hours of reserves" is significantly less than that spent holding at a few thousand feet. Fuel efficiency while climbing is yet again dramatically worse
I thought a lot of airlines had rules to limit the number of attempts you could make at a single airfield in an attempt to prevent this exact kind of situation.
It sounds to me like they tried harder at their intended destination than maybe they should have, followed by going to an alternate airport that probably wasn’t a good choice in the first place, and then having to divert to the final airport where luckily they could land in time.
I'm not an aviation expert, but generally in safety engineering, safety buffers are not simply calculated as [normal situation] * [safety factor], but [worst case scenario] * [safety factor]
If you ever cut into your safety allowance, you've already fucked up. Your expected design criteria should account for all use cases, nominal or worst-case. The safety factor is there for safety, it is never intended to be used.
This is really helpful and I think I understand now.
The approach is basically “accounting for everything that might go wrong to the best of our experience, including problems arising from the complex interactions between the airplane and supporting ground systems and processes, this is how much fuel you need in the worst case scenario. And now lets add more to give us a cushion, and we will treat consumption of this last reserve as tantamount to a crash.”
This is exactly how it is in this case. Any consumption of the fuel reserve would result in an investigation, this is a very extreme case and it may even result in a change in the rules depending on the root cause.
Yes, exactly. The day it's normal to eat into the allowance is the day we start seeing planes falling out of sky for lack of fuel again. The only way to prevent that is to treat 30 min of fuel as seriously as you would 0 minutes.
Why not? It's a factual report stating that the AAIB has opened an investigation into a potentially dangerous incident. There's not any editorial bias evident. See other extensive comments as to why this is not just a case of "it landed, so what's the problem?".
Or did it work as intended? The plane had multiple failed landing attempts, was re-routed, and had enough fuel to land safely. While no one wants to cut it this close, this was not a normal flight.
I’m not an expert in this field, but it would seem that the weight of extra fuel would increase operating costs, so it’s is effectively insurance. How much extra fuel should be carried to account for unplanned events like this, while not carrying so much that it becomes cost prohibitive.
That example is so well known due to how exceptional it was, especially how the pilots handled it. Robert Pearson, the captain, was a very experienced glider pilot. That's something that not many commercial pilots have.
There were also two factors in the landing, that allowed for this to happen. You're going to be coming in really fast for a landing, when gliding in a commercial jet, and you don't have access to your thrust reversers to slow it down. There was a repurposed runway, that they used to land, that just happened to have been used as a drag racing track and had a guard rail. They were able to slow down by scraping across that. It also just so happened the nose gear didn't deploy fully so scraping the nose of the plane against the ground also helped slow it down.
Needless to say it was a bunch of very fortunate events that allowed it to not end in disaster. In any case I would consider it very risky.
The "scraping helped slow it down" theory makes no sense to me. What do you think has a higher coefficient of friction - tire rubber on asphalt, metal on asphalt, or metal on metal?
I would hesitate to chalk it up to just theory, given it was in the NTSB report and they don't really mess around with throwing baseless stuff around. I'd be interested to take another look at it. They likely go into the material science and physics behind this very thing. They're usually filled with gems.
You also have to keep in mind, it wasn't just rubber against asphalt, it was rubber on a wheel that spins. I'm not sure if the front nose gear on a 767 has any brakes but even if it did, I can't imagine it would be sufficient at the speeds they were going.
I mistyped, as this was Canada it wouldn't be the NTSB but the Canadian equivalent at the time: Canadian Aviation Safety Board. The report is a good read.
Rubber likely grips much better than metal, however three wheels have massively lower surface area than the body of the plane, or even a small section of it like the head.
Of course we don't land tireless for other reasons (metal transfers heat exceptionally well unlike rubber, paint doesn't survive high speed impact, and it tends to deform upon impact with anything, making any future flights unsafe), but the fastest way to slow down if you don't care about safety or comfort would probably be to land tireless, if you could introduce some rotational spin, that might be faster (more force directed in multiple directions).
Also, on the note of "coefficient of friction", remember that this number is not just some innate property of a molecule - as the metal scratches the pavement and deforms, its coefficient of friction goes up as micro-deformities accrue.
Fuel depletion is stupendously risky, it is one of the most risky things that can happen to a jet. The only things more dangerous are fire and control systems failure.
The Gimli Glider was a case of many items of luck lining up.
I know you're trolling, but for anyone that hasn't heard of Gimli Glider, look it up or watch a documentary on youtube. The stars definitely aligned to make that happen.
Fuel depletion is _not that risky_ is an interesting take. But hey, it won Chapecoense its first and only Copa Sudamericana, so maybe it isn't that bad after all?
You could've read at least the Wikipedia page on how miraculous Gimli Glider was.
From "all engine failure is never expected and not covered in training" to "Pearson was an experienced glider pilot familiar with techniques rarely needed in commercial flights" to the amount of maneuvers they had to execute on a barely responding aircraft
Well imagine they had to do a go-around on that landing. Go-arounds are extremely normal and might be done for a million reasons; your speed is wrong, your descent rate is wrong, your positioning is wrong, there's bad wind, there's an issue on the ground, etc etc etc. Six minutes of fuel is really not enough to be sure that you can do a go-around. So now, if ANY of those very normal everyday issues occurs, the pilot has to choose between two very bad options: doing a go-around with almost no fuel, or attempting a landing despite the issue. That's just way too close for comfort.
Aviation operates on a Swiss cheese model; the idea is that you want many many layers of safety (slices of cheese). Inevitably, every layer will have some holes, but with enough layers, you should still be safe; there won't be a hole that goes all the way through. In this case, they basically got down to their very last slice of cheese; it was just luck that the last layer held.
Depends if our goal is to have zero aircraft crashes. If the goal is zero, then for any given parameter, you have to define a margin of safety well before crash territory and treat breaching that margin as seriously as if there had been a crash.
Similarly planes are kept 5 nautical miles apart horizontally, and if they get closer than that, you guessed it - investigation. Ofc planes could come within inches and everyone could live, but if we normalize flying within inches, the we are also normalizing zero safety margin, turning small minor inevitable human failings into catastrophe death & destruction. As an example, planes communicate with ATC over the radio and are given explicit instructions - turn left 20 degrees, fly heading 140 etc. From time to time these instructions are misunderstood and have to be corrected. At 5nm separation everyone involved has plenty of time to notice that something was missed/garbled/misinterpreted etc and correct. At 1 inch separation, there's no such time. Any mistake is fatal, even though in theory you are safe when separated by 1 inch.
TBC an investigation doesn't mean investigating the pilots in order to assign blame, it means investigating the entire aviation system that led up to the breach. The pilot's actions / inaction will certainly be part of that, but the goal is to ask, "How could this have been avoided, and ask how every part of the system that we have some control or influence over might have contributed to the outcome"
We shouldn't aim for 0 crashes due to low fuel though. How many deaths does carrying around 3x fuel than what you reasonably need contribute to via extra pollution?
We should aim for 1 every 10-100 years or something reasonable like that.
We should account for deaths from pollution, but if we are going to do that, we should be willing to do that for 99% of aviation fuel that has nothing to do with reserves & safety margins, in addition to fuel used to drive cars.
Any regulation short of "carry infinite fuel" will be a trade-off, and entail some risk and anyone involved in setting these knows that. Zero may not be our actual target or even possible, but it is a useful aspiration to ensure that everyone is pulling in the right direction.
If they have to touch and go, how long would it take until they get the plane around for another approach? In fact, you might not get as far as that touch and go and have to go around. You need some margin for all of these eventualities. The likelihood is low that these happen, but they have to be accounted for.
Sure, but the flight was a lot longer than planed. How much extra do we need. They declared an emergency, and thus put themselves at the front of the line. They had 6 more minutes to do that touch and go around if that happened, and since they were already in a low fuel emergency they get priority and so there is enough time to do that if they needed. (edit - as others have noted, 6 minutes with high error bars, so they could have only had 30 seconds left which is not enough)
They landed safely, that is what is important. There is great cost to have extra fuel on board, you need enough, but it doesn't look to me like more was needed. Unless an investigation determines that this emergency would happen often on that route - even then it seems like they should have been told to land in France or someplace long before they got to their intended destination to discover landing was impossible.
Correct, article says they landed with 220kg which is around 6 minutes of average fuel burn over an entire flight - bit less at cruise, a hell of a lot more at takeoff/climb.
So I don't think 220kg is enough to do a go-around in a 737 (well, a go-around would've been initiated with a bit more than 220kg in the tank - they burned some taxing to the gate - but you get my point.) I've read around 2,300kg for takeoff and climb on a normal flight in a 737-8. A go-around is going to use close to that, it's a full power takeoff but a much shorter climb phase up to whatever procedure is set for the airport and then what ATC tells you.
I just flew 172s but even with those little things we were told, your reserve is never to be used.
These people came very, very close to a disaster. Fortunately they had as much luck left as they did fuel.
That could be. We just don't know right now, but your intuition may well be correct, even if there is a single root cause there could very well be multiple contributory causes.
Could have, but pilots practice no fuel landings all the time (in simulators). If they can get to ground that is "level enough" nobody dies. It is not something you ever want to see in the real world (and in the real world people often do die when it happens), but it isn't automating people die.
I don't think that's all that true for airliners. Pilots definitely practice for engine-out scenarios during all levels of training up to the airlines, but the ability of a plane the size of a 737 to safely land on anything but a runway is...limited. And if you're low, slow, and trying to go around, that's not a lot of time to glide to ground that is "level enough".
How much extra do you need? Enough that a pilot/crew doing their job properly will never run out of fuel and crash.
So yes they will do an "investigation". It's not a criminal investigation. It's to understand the circumstances, the choices, the procedures, and the execution that ended with a plane dangerously close to running out of fuel.
This will determine if there were mistakes made, or the reserve formula needs to be adjusted, or both.
Don't tell me about cost, just stop. Let MAGA-Air accept some plane deaths to have cheap fares.
Pilots are ultimately responsible for the aircraft, that's pretty much set in stone but if ATC would tell them to divert they would unless there already was an emergency.
Naively as an outsider, this situation seems like everything worked as intended?
I don't remember all of the rules off the top of my head, but if you are ever landing with less than 30 minutes of fuel, something has gone seriously wrong. You are required to take off with sufficient fuel to fly to your destination, hold for a period of time, attempt a landing, fly to your alternate, and land all with 30 minutes remaining. If you are ever in a situation where you may not meet these conditions, you are required to divert immediately. In choosing your alternate, you consider weather conditions along with many other factors. This was, without question, a serious emergency.
From the very brief description in the article, I would say they should have diverted to Manchester at least 25 minutes sooner than they did. I will include the GP's caution, however:
I'd be very wary to get ahead of the investigation and make speculative statements on how this could have happened, the one thing that I know for sure is that it shouldn't have happened, no matter what.
This reminds of discussions following the Fukushima disaster where one commenter claimed that it wasn't a design flaw, because it was an extraordinary circumstance. I found this appalling, because I do not at all think that was the risk profile that was sold to the public; I think people believed that it was supposed to be designed to safely survive 1000-year earthquakes and the tsunamis that they create.
Likewise, I think that the flying public is lead to believe fuel exhaustion is so rare that when airlines are compliant with regulations, no such disasters across all flights across all carriers will occur during your lifetime.
It's also a communication problem, because labels like "100-year/1000-year event" are easily misunderstood.
* they're derived from an estimated probability of the event (independently) happening each year. It doesn't mean that it won't happen for n years. The probability is the same every year.
* the probabilities are estimates, trying to predict extreme outliers. Usually from less than 100s of years of data, using sparse records that may have never recorded a single outlier.
* years = 1/annual_probability ends up giving large time spans for small probabilities. It means that uncertainty between 0.00001% and 0.00002% looks "off by 500 years".
My understanding is that they shouldn't have spent that much time in the air (not intended as a guess for the cause). The margin is there for situations where you can't land earlier, not the margin for scheduling the landing. There is margin for expected potential delays, they were in the other margin that should never be used except in true emergencies.
Oh I think I see; so is the question not “why did they land with so little fuel”, but more like “why did it take so long to decide to redirect to a known-safe airport”?
Possibly. Or 'why did your fuel readings deviate from what was actually in the tanks' or 'why did we leave with less fuel than we thought we did' and so on. There are so many variables here speculation is completely pointless. All we know is that something went wrong, that it almost led to a crash and that it involves an airline with a very good record when it comes to things like this.
I don't know. As the parent said, I'd be careful with guessing the root cause right now. They should not have been this low even if diverted due to weather.
Only issue I see is that should there have been stricter rules to diverting way earlier. If winds were such as to make landing harder. Would just directly going somewhere else been the correct choice to force.
Well, if you know you're pretty low on fuel, you are likely to pick an airport where the weather is good, rather than risking three more missed approaches at a closer one where the weather is probably also bad.
Of course, Manchester is also a Ryanair base. There are two Ryanair bases closer to Prestwick (Edinburgh and Newcastle), but maybe the weather was bad there too? If the fuel situation was so dire, questions might be asked during the investigation why they didn't pick a closer airport with good weather that wasn't a Ryanair base (if one existed), but ultimately it's the pilots' decision to fly a bit further to an airport they are familiar with, and second guessing them with the benefit of hindsight is probably not a good idea...
One of those YouTube channels where a professional pilot evaluates flying incidents had a similar incident when the pilot started yelling at the tower when they tried to make him go around again. He essentially said he would declare an emergency if he didn’t hear different instructions. I think he had 10-15 minutes when he touched down.
One of the things the reserve is for is if the plane immediately in front of you fucks up the runway, you now have to divert to the next airport. You need at least enough fuel to get there and for the tower to shove everyone else out of the way so you can make an emergency landing.
There are other reasons someone could abort a landing and have to go around again, besides debris in the runway. And sometimes two of them can happen consecutively.
In the case I’m referencing, it was pointed out that p the pilot made things worse by going faster than he was told to fly, using up fuel and also making him too close to a previous plane which forced him to go around the previous time, so it wasn’t all the tower.
> I’m a little confused by what there is to investigate at all.
So because the safety margin still worked while down to near vapors we should conclude there's nothing to learn for the future to reduce the risk of similar incidents?
>I’m a little confused by what there is to investigate at all.
One of the most important aspects of taking safety seriously is that you do not just investigate things which had an impact, but that you proactively investigate near misses (as was the case here) and even potential incidents.
A plane with 6 minutes of fuel left is always a risk to every person on board and potentially others if an emergency landing becomes the only option.
Indeed that is the definition of a "aviation incident" where there was a risk of injury or damage. If there is actual injury or damage it becomes an "accident".
The investigations into incidents aren't usually particularly long or noteworthy and often the corrective action will be to brief X on dangers of Y, or some manner of bulletin distributed to operators.
Flight from Edinburgh to Manchester is just a bit more than 1 hour, so after trying 2 landings, diverting to Edinburgh (15-20 minutes flight), 1 more landing attempt, well, you get very close to 2 hours.
I think a more insightful answer is how often is it acceptable for the reserves to actually be cut into. If this was happening often, then there’s a likelihood of a future disaster. As it is there is 1 isolated case that still ended with a positive outcome. I think it almost adds support for the current reserve levels to be pretty dialed-in.
Officially: never. Unofficially, a minute or two would be cause for concern and the regulators would most likely be showing an interest. The airline may have a higher margin than the official one. This is exceptional, they were within the margin of error on readout and the pilots must have known that. It's one thing to know you have half an hour of fuel give-or-take in the tank it is another to know that give-or-take you are running on fumes.
The answer is 'never' as the reserves are only added for worse-than-worst case scenario, i.e. in this case something went literally unimaginably (as of then) wrong.
6 min, is empty, 6 min is purely theoretical, 6 min would not clear for ground handling or a test start, or a fuel system check,6 min would not do a go around.
will interesting to see if they release info about what the real amount of fuel left is, and an authorative discussion on how much useable flight time was there.
did they actualy make the taxi to the terminal?, or run out on the apron?
Yes. There is another comment above making light of the 6 minutes as if another go-around was still an option, that is a ridiculous take. They were going to bring that plane in and land it no matter what on this last run, otherwise they'd crash for sure. 6 minutes may not even be within the margin of readout.
Imagine you're standing on a balcony and discover that the supports are cracked almost all the way through.
Do you shrug and say, that's why they have a safety factor, everything worked as intended? Or do you say, holy crap, I nearly died, how did this happen?
The purpose of the safety factor is to save you if things go badly wrong. The fact that it did its job doesn't mean things didn't go badly wrong. If you don't address what happened then you no longer have a safety factor.
Whether it can be prevented in the future. Should planes fly with even more reserve fuel? It's possible. Or maybe different ways of selecting alternate landing sites?
It may even be the answer is "no, everything went as well as it possibly could have, and adding more reserve fuel to every flight would be unacceptably wasteful, so oh well", but at a minimum they'll probably recommend even more fuel on certain flights into risky weather.
Anything less than 60 minutes would be looked at by the airline, anything less than the legally required amount (30 minutes for a jet of this type iirc) will result in a very serious investigation. Note that for slower aircraft (for instance a turbo-prop) the time requirement goes up not down because they may have to spend more time in the air to reach an alternate (or secondary alternate, if things are really bad, like what happened here).
I have known former air traffic controllers that won't fly certain airlines because of a notorious habit some have for queue jumping by claiming they're low on fuel. If they are low on fuel is something else, but in any case when the ATCs have noticed a pattern then something is up.
This situation sounds a lot less nefarious, but it does also sound like they should have rerouted earlier.
Since there's a lot of confusion in the comments below I'm going to hijack one of the top comments to make a couple points clear from the article and FlightRadar24 data: [1]
They did reroute earlier. It was 2 failed attempts on Prestwick (Glasgow), 45 minutes in the landing pattern, then they diverted to Edinburgh (15 minute flight), a failed attempt at Edinburgh (~5-10 minutes), and then they diverted to Manchester (45 minute flight) and landed successfully there. Likely they hit their reserve just as the Edinburgh landing failed and decided to fly to Manchester, with clearer skies, rather than risk another failure in their reserve.
IMHO the only questionable pilot decision here is to divert to Edinburgh rather than Manchester immediately. But this is somewhat understandable: first of all, dropping the passengers off at Edinburgh (an hour drive from Glasgow) is significantly less costly and less inconvenient than dropping them at Manchester (an overnight bus ride). Second, if the Edinburgh landing had been successful they would not have eaten into their reserve and no investigation would've been needed. Third, the Monday-morning quarterbacking could've easily gone the other direction if they had diverted to Manchester ("Why did you choose an airport 178 miles away and risk eating into your fuel reserve when Edinburgh was right there?")
> IMHO the only questionable pilot decision here is to divert to Edinburgh rather than Manchester immediately. But this is somewhat understandable: first of all, dropping the passengers off at Edinburgh (an hour drive from Glasgow) is significantly less costly and less inconvenient than dropping them at Manchester (an overnight bus ride).
Yeah, as someone who knows next to nothing about airlines, but has seen these type of decisions in businesses, this was the thing that stood out to me. This is all pure speculation of course, but I'd be curious how clear it was that Edinburgh would also have a high risk of being unsuccessful and whether the pilots felt any pressure to try that anyway. E.g. are there consequences for pilots who cause delays for passengers?
At the point they left it, they still had about an hour and 20 minutes of fuel remaining, with an alternate airport 20 minutes away. They had not declared an emergency, so they were in with any other traffic waiting for takeoff and landing. (Which does make me wonder, did any other planes try to land at Prestwick at the time and how did they fair?)
Quick note that Preswick is not really Glasgow (35 miles away) and Glasgow has its own airport which presumably was also affected by the same weather so they couldn't divert to that. Between the Scottish lowlands (where they had already tried all the commercial airports) and anywhere else, Manchester is about the closest option.
As someone totally ignorant of British airports, a Google maps search for "airports northern england" shows Teesside, Carlisle, and Newcastle all significantly closer to Edinburgh than Manchester. Are these not places where a 737 under emergency could land? Or was the weather also bad there?
Carlisle is small (and not currently licensed for public use) - not an ideal place to drop a 737 if there's a choice. It's also not that far from Prestwick so may have had similar weather. Newcastle and Teesside are both on the East coast and likely to be affected by similar weather to Edinburgh given the storm coming in from the North East. The next closest will be Manchester or Leeds/Bradford, with Manchester being larger, closer to where passengers want to go (Glasgow) and further away from the storm.
There's precedent for this kind of situation to generate quite extensive investigations. An incident in 2017 where a flight from the Isle of Man to Belfast was unable to land in a storm, diverted back to the IOM, then landed in unsafe weather conditions because of insufficient fuel to divert again got a 48 page report[0], safety recommendations, and the airline being banned from the UK.
That's likely, these places are not very far apart, and weather systems that cause 100mph winds don't tend to be small. And presumably if you have at most one landing attempt remaining you don't want to be taking any more chances.
Claiming you're low when you are not is going to cause a major headache for the PIC, they're going to have to write that up and they may well be investigated. If it turns out they were lying they would likely find out that that is a career limiting move and if it happens too often then that too should result in consequences. The main reason is that your fake emergency may cause someone else to have a real one.
When you declare a fuel emergency or even urgency, there's often follow up to figure out why (mechanical issue? problem with dispatch? problem with flying technique? exceptional weather condition that could be forecast better? etc). And there is plenty of data in aviation to know what happened.
Dispatch knows how much fuel they say they put in.
Your flight time, speeds, and profile are known.
ACARS may be reporting fuel use throughout the flight.
Random spot checks. Every day at every airport some of these will get verified. Also, the next pilot would have to be willing to cover for you because they are going to have to falsify their records to make your trick invisible. You record the amount of fuel in the tank when you take command of the aircraft, the amount of fuel that was loaded and from that it is trivial to compute how much was left the last time it landed.
When someone accepts the writeup, there's a random chance it's selected for followup. If/when they discover there was enough fuel, it will affect the career(s) of person(s) involved.
First, generally, people don't like having to do paperwork, and especially don't like doing paperwork to help you land a little quicker.
While one time may not be a fireable offense, you will find you career affected in the number of ways people can find to be uncooperative with you, or not support you when you attempt to advance your career within the company.
Developing a habit would lead your interlocutors to escalate the situation, which would lead to discipline up to and including the company firing person(s) involved.
Edit: I was recalling articles claiming the company purposely fueling less than other airlines in order to increase their rate of claims for priority landing to have a better "on time" statistics.
Having attended meetings at ICAO I can also tell you many details of various aviation incidents, including their existence, are covered by some secret classification. This fact being disclosed caused most of the attendees to lose all hope in the rest of the proceedings. To their credit the FAA reps on that occasion were by far the most reasonable gov representatives in the room, and the FAA are one of the major voices pushing for greater transparency on it.
It’s generous of the classifying authority to send to the ICAO meeting somebody both appropriately credentialed to know about the information in question, and willing to talk coyly about it. Did these additional incidents inform the policy discussions at the meetings you attended?
It's funny you say that, because the way it happened was it was blurted out by a diplomat from a certain country, at which point most of the regulators facepalmed and all of those of us from outside were having the same reaction as many here.
The whole subject of discussion prior to this was efforts to improve data sharing wrt incidents.
Second guessing a pilot saying they have a problem is a really bad idea. ATC second guessing an emergency is a really bad idea. Making a pilot explain why they're actually low on fuel, despite whatever some computer is saying, instead of focusing on flying the plane is a really, really bad idea.
Also, that sort of telemetry does exist for most major airlines, however it goes via satellite to the airline not the ATC.
I am not saying you are wrong, but both Type I and Type II errors are problematic. What if the pilot is wrong?
Korean Air Flight 801 could have used someone 2nd guessing a pilot. They didn't until they were almost dead and then it was too late. Not 2nd guessing the pilot was a really really bad idea.
If the pilot is wrong you hope the copilot or someone else on the crew picks up on the error and corrects it. If they’re both wrong, or if they don’t feel empowered to challenge the pilot like in Korean Air 801, everyone is usually fucked.
ATC doesn’t have the kind of situational awareness or manpower to fix these kinds of problems the vast majority of the time. It only seems like they could have done something after the fact when the disaster has already happened and hindsight activates.
Like the GP said, ATC second guessing pilots is a really, really bad idea. A few incidents doesn’t change that.
> Korean Air Flight 801 could have used someone 2nd guessing a pilot.
...yeah, the second pilot. And in this case, also flight engineer.
IIRC The problem was pretty much aside from errors the cultural issues with pilots, the "lower ranks" wouldn't dare to be assertive to seniority and just voiced the issues they saw without doing anything.
I expect that they take the pilot's word in case of a rare situation [1] and then make the fill a ton of paparwork to try to solve the main cause and also discourage lies.
[1] In one case someone mixed imperial and metric unix, and instead of $something-kilograms, they put only $something-pounds of fuel.
This incident is known as the Gimli Glider and was actually due to multiple failures before the pound-kilogram issue (and the backdrop of Canada's then-recent metrication) even became relevant: https://en.wikipedia.org/wiki/Gimli_Glider
Minimum fuel requirements are calculated as "Time of fuel for cruise to certain points", which is usually good enough, but if an Airport is stupid busy, or has bad wind patterns, just a couple go-arounds will chew through your fuel way faster than the regulation expects.
Turbofan engines are also dramatically less efficient at low altitude than high altitude cruise. So holding at low altitudes because a congested airport is dealing with traffic will chew through your reserves much faster than you expect.
Ryanair flies short hops to congested airports. They will have relatively low reserves, and you should expect them to run into "Hey we are low on fuel" more often than international flights for example.
It is almost fascinating how humans will stoop to dishonesty even in banal situations - and not just any humans, but pilots, who should be subject to at least some vetting.
Maybe planes should be retrofitted as to transmit their actual fuel state including a qualified assessment in minutes to the ATC. Not just because of the cheaters, but also to warn the ATC in the rare case that some plane crew isn't very assertive about their dwindling fuel, or hasn't noticed the problem.
It would make prioritizing the queue a bit more neutral.
If I designed such a system from scratch, "remaining fuel" would be part of my telemetry.
And the reason why those fuel reserves exist is to be a guard band allowing situations like this to happen without flames, wreckage, and death.
Having worked with many US airline pilots over the years, this is also why they are so proud to be unionized. Sure, senior pilots make as much as some FAANG developers, but the union is also there so that management doesn't get bright ideas about things like cutting fuel reserves to cut costs without the union telling them to stuff it.
Management can't cut fuel reserves, not because the pilots are unionized but because there are some very strict rules about these fuel estimations prior to take off and margins be damned. And those rules are exactly there because otherwise this kind of incident would happen far more frequently. But it's regulation that is the backstop here, not the pilots.
The point is that the unions are there to allow the pilots to advocate for all kinds of safety-of-flight related things like fuel reserves, crew rest, and so forth that management would be happy to cut to save money. And to do so without fear of retaliation.
And if you don't think the airlines would love to lobby Congress about the regulatory backstop, well . . .
As I wrote elsewhere in this thread I actually wrote software to estimate the amount of fuel a jet should load to comply with the rules. This was commissioned by the airline and they were scared shitless that they would ever be found to be in breach of the regulations on this aspect. It is one of those red lines that you really do not wish to cross. There are other aspects of flight where you are right but this particular one is different.
The main reason why airlines would like to take the least amount of fuel is because it immediately increases payload capacity and thus flight efficiency. This being a cut-throat market there is a serious incentive to cut it as fine as possible. So the regulations around this particular issue are incredibly strict: you have to have a certain amount of fuel left upon landing, you have to write up truthfully how much you still had left and you will be investigated without fail if you cut into the reserve. The good thing about unions here is that they help to make sure that pilots know they are safe reporting truthfully because the airlines can not retaliate if they would pressure the pilot to not report an incident (which all pilots would normally definitely do). So they're a factor, but it is the regulator that writes the rules here and they are super strict about this.
And that's immediately why the calculation of the estimate becomes so important: you now have 30 minutes (or 45, depending) of deadweight + the deadweight for two alternates and an x amount of time in a holding pattern, plus up to three go-arounds. That really adds up, so you have to do your best to get the calculation as close as possible to what it will be in practice without ever cutting into that reserve.
It took me the better part of a year and massive amount of learning to write a small amount of code + associated tests to pass certification. It also taught me more about software engineering (as opposed to development) than anything I did up to that point in time and it made me very wary about our normal software development practices.
I think the literal fear of death _might_ be motivation enough for pilots to advocate for safety? And if they want to fire you, would you want to work for them anyways?
> I think the literal fear of death _might_ be motivation enough for pilots to advocate for safety?
You'd think, but individual humans are very very bad at estimating risk, and in toxic group and work situations, humans will often take on increased personal risk rather than risk conflict. I.e., they will value group conformity over their own safety ... especially if their paycheck is involved. Fear of death is not nearly as powerful as robust regulation and unions.
The union is a nice backstop for issues around the edges that come up with corporate, but the real backstop is the pilots’ licensing. By making them directly responsible for the plane as PIC, it gives them leverage over their employer that few other professions have. AIR-21 gives them significant protection from retaliation and the ASRS is confidential. ALPA helps them navigate that mess if it comes to it, but that’s the real legal backing that pilots have.
Same thing happens with Professional Engineers regardless of whether they are employed or work as independent consultants/firms. They’re legally responsible for the bridges and other infrastructure they sign off on with laws protecting them from employers and clients.
(I fully support the ALPA and other unions, I just don’t think it plays as significant a role in following regulations as you claim)
...that regulation is text in a database. It can be changed capriciously at any moment, like they often are.
It takes people with ideas and a willingness to put pressure in the right places to be sure that sane policies prevail.
I think it's pretty obvious that as time moves forward, we need to rely on "regulations" less. The root and history of the word in the political context is to make things regular. But state actions increasingly bring irregularity to the world.
It seems absolutely fair to say that, in this situation, the people - the pilots in particular, but also cabin crews, ATCs, engineers, and their unions, are the backstop worth observing and celebrating.
If you land with less fuel than the legal minimum you are going to have a lot of explaining to do, there will be an investigation and you, the pilot and the airline will get enough headache from it that you will make bloody sure it does not happen again. The pilot(s) may not be able to fly until that investigation has run its course, the airline may get fined or warned if this is the first time it happened. In an extreme case the pilots may lose their license.
> It seems absolutely fair to say that, in this situation, the people - the pilots in particular, but also cabin crews, ATCs, engineers, and their unions, are the backstop worth observing and celebrating.
I will hold off on that conclusion until the report is in. There are so many possible root causes here that speculation is completely useless, and celebrations would be premature.
My apologies - I didn't mean to speculate about this incident in particular, but about the general role of so-called "regulation"; I thought it was unfair to minimize the role of the people and unions compared to the (in my view, comparatively flimsy) legislation.
I think the thing that's being pointed out as overlooked when praising the employees and the unions, is the regulators, who are the people who play a very large part in making sure that the regulations are enforced. The regulations are just text in a database, but it's the regulators who actually make it happen. A pilot who wants to push back against a beancounter cutting corners has a union and a regulatory agency to back them up.
Yes. I think the average bus and train driver is completely underappreciated as well and they have a massive responsibility too. I know I could not do their jobs, it would weigh on me too much.
> I'd be very wary to get ahead of the investigation and make speculative statements on how this could have happened, the one thing that I know for sure is that it shouldn't have happened, no matter what.
Just watch Juan Browne, he usually turns out pretty good in analyzing the mishaps. He didn’t upload anything for Manchester yet but will probably soon: https://youtube.com/@blancolirio
I remember this stuff being a bigger story for a short moment x years ago, where low cost carriers (it might have been Ryanair then, too) routinely flew with unreasonably small amounts of "backup" fuel and had to declare emergencies in order to get on the ground safely.
I guess they're trying it again now that the whole thing had blown over.
3 go arounds + 2 hours in a holding pattern should result in at least 45 to 60 minutes left in the tanks after landing. Depending on the kind of aircraft that can be a pretty impressive amount of fuel.
> Does the estimation change depending on weather forecast, season of the year etc?
Yes. There are many factors that go into this including trade winds (which vary quite a bit seasonally and which can make a huge difference), time of day, altitude of the various legs, route flown, weather, distance to alternates, altitude of the place of departure and altitude of the place where you are landing, weight of the aircraft, engine type, engine hours since last overhaul, weight of passengers, luggage and cargo, angle-of-attack and so on. The software I wrote was a couple of thousand lines just to output a single number and 10x as much code for tests, and it was just one module in a much larger pre-flight application.
The test suite was much larger than the code. It took ages to get it certified, the calculations had to be correct to the last significant digit on reference problems to prove that the algorithms had been implemented correctly. This caused a bit of a headache because the floating point library that I used turned out to be slightly different than the one from the benchmark.
There are three different kinds of jet fuel and all are produced to strict standards, and then there are allowances for ppm water contamination (very low, to ensure the fuel system will never freeze at altitude or in freezing weather on the ground or at lower altitude).
Yes. Even not forecasted storms in the form of a probability of wind at low altitude when the engines are at their least efficient. And tradewinds at altitude, which are quite variable as well.
This honestly makes me think that we're missing a trick if an option for this sort of circumstance can't be "send a military fuel tanker up to refuel them in air" as a last ditch emergency measure (which IMO you would've triggered in this exact scenario).
The argument in favor is simply that we need in air refueling for the military, but justifying all that expenditure is a lot easier if it's dual use technology.
Under FAA rules this was a screwup. [edit: see my own reply] (However, the rules are subtle, so they can be partially forgiven.) However, I'm not only a dispatcher but also a philosophy BA, so I've found a good way to explain it.
Your reserve fuel (the "extra" fuel over what the actual flight burn) can of course be used (hello, that's what it's there for) but—and here's the rub—you can never plan on using it.
That is to say, in this case, when they missed their first or second approach, they CANNOT say, "We'll use our reserve fuel and make another go at it" because that would be intentionally planning to burn your reserve.
You may only dip into your reserve when you have no other choice. In this case, when the only fuel they had left was reserve, they are obligated by law to proceed to the alternate airport, which clearly they did not do [correction: they did do the proper thing; see my 2nd reply below]. No bueno.
[this is a slight simplification (minor details omitted for brevity) but the kernel of the issue is properly described]
Update: OK, if *Edinburgh* was their alternate and they missed there and were then forced to bugout for Manchester, that's then an example of when reserve is OK to be burned. (The 'slight simplification' I omitted was unpacking how the alternate fuel plays into the process, but here, that was a key part of the series of events.) That's what I get for not reading TFA first :-/
Not really, you should have enough fuel to make it to multiple alternatives or make emergency landing somewhere else. You should never burn that last 45 mins unless you want to make the news and file a lot of paperwork.
The regs are quite specific on if and when we need an alternate, which is weather dependent, and what your fuel requirements are. And we don't really have the idea of "multiple alternatives", but I guess it's implied by the additional reserve - what us Americans call a reserve or the Europeans call "final reserve". In case you're curious, we use the TAF (termimal area forecast) to determine if we need an alternate, and use a 1,2,3 rule which is 1 hour before and 1 hour after arrival time we need ceilings of at least 2000 ft and 3 statute miles of horizontal visibility.
The sequence was [depart Pisa => Prestwick (2 missed approaches) => proceed to Edinburgh (1 missed); declare Mayday fuel => proceed to Manchester (land on first attempt)]
I'm curious why you did that? It's not a very complicated sequence. The whole point of engaging in a discussion here is to think about the issues raised and offer a point of view while incorporating other perspectives into yours. You've spent your money to bypass the whole intent of this site; akin to you being hungry then sending someone else to a restaurant for you so you can later read their review of the food.
EDIT and you of most of the commenters here, with your industry background, are better placed to offer an opinion!
Presenting information in different ways is useful (and the method of display can offer informational insights itself). And for different users it might help parse larger connections. And by using the LLM to summarize just that one facet of the problem (itinerary and sequence) and sharing it here, they’ve contributed in a meaningful way. It may not have warranted a response. But it added to overall understanding of the problem space to help facilitate discussion. And they did well enough by citing that the info came from an LLM. They didn’t bypass the intent of the site. They added to it and fell right in line with that intent.
I had no issue with the contribution itself, the route summary is helpful.
> And they did well enough by citing that the info came from an LLM.
In terms of acknowledging AI contribution, you're damned if you do, damned if you don't. Here it's sidetracked a discussion; but transparency is better than otherwise I suppose. Perhaps it just boils down to taste - and I don't like it.
Even though I’ve read the entire article, I found it very difficult to mentally visualize and ended up not noticing that there were three destination airports involved.
> That is to say, in this case, when they missed their first or second approach, they CANNOT say, "We'll use our reserve fuel and make another go at it" because that would be intentionally planning to burn your reserve.
Is that what happened? That's not in the article, what's the source?
And other comments here are saying the third attempt was in Edinburgh, so they were already trying to land anywhere possible by the third attempt.
At what point are you saying they chose to plan on using reserves when they still had any option for landing without reserves?
Not necessarily. And I get that you've caveated yourself with an edit and a reply etc, but lets assume that you're not hedging for the moment.
They carried required reserves on departure. Multiple approaches thwarted by extreme unforseen weather. They declared Mayday Fuel, which is mandatory under EASA regulations, when reserve fuel use became unnavoidable. They diverted to the nearest suitable airport.
Landing with 220kg is close, but within bounds of a declared fuel emergency.
Crew decision to declare Mayday and divert was proper airmanship, not negligence.
Yes, reserve fuel may not be planned for. But it may be used. It's there for a reason. Your accusation doesn't account for dynamic evolving weather and realtime decision making.
I'm an instrument rated pilot and an advanced ground instructor under FAA and I fly IMC in bad weather as single pilot IFR around the pacific northwest and colorado.
Was this good/bad? Idk Room for improvement? Maybe? Clearer direction with the benefit of hindsight? Maybe. but the majority of the sentiment in the responses is coming from people not type rated in a 737.
Similar philosophies but with differences. e.g. FAA reserve requirements is destination + alternate + 45 mins reserve. EASA is destination + alternate + final reserve which is 30 mins holding for jets and 45 mins for pistons IIRC. But in both cases it's that idea of a destination, an alternatite, and additional. And then there's the requirements around whether you need an alternate, etc.
Looks like they tried two attempts to land in Prestwick over two hours, then flew to Edinburgh and made one aborted landing, then finally went to Manchester.
What a nerve wracking experience for those pilots. I wonder if on the final attempt they knew they had to force it down no matter what.
Per the FlightRadar24 logs, it looks like only about 45min was wasted over Prestwick, not 2hrs. First approach was around 18:06, and they're breaking off to head for Edinburgh by about 18:51.
If there's considered to be a mistake here though, I'm guessing it's going to be spending too long before committing to the initial diversion.
Without knowing the weather they were seeing at the time, seems hard to say if they should have gone for a closer 2nd alternate than Manchester.
I don't think we know yet when min fuel was declared. At that point, they will be resequenced. Then we need to know when mayday fuel was declared. It sounds pretty odd, like perhaps there were multiple simultaneous situations and the crew did not have adequate information.
It is a requirement [1] to land with 45 minutes of fuel remaining, if the pilots go under that, it is considered an incident. As soon as estimated landing fuel goes under the limit, the flight needs to declare an emergency (as was done in this case).
They got within a hair of crashing, there is nothing impressive about this. 30 minutes, ok, you still get written up but this is cutting it way too fine.
Either this is true, or this is why there’s a 45 minute reserve requirement. There were three failed landing attempts in two airports prior to the successful landing, and they spent almost as much time attempting to land as the scheduled flight took.
Seems like this was exactly the scenario it was designed for?
I would imagine 6 min fuel left was designed for something extreme. Maybe involving damage to aircraft limiting where it can land etc. Or extreme weather event such had high winds affecting all airports within 500 miles.
No, this is what should never happen. I wrote fuel estimation software for cargo 747's and the one thing I would have never ever wanted to read is that an airliner of the company I worked for had landed with too little fuel.
About 5 years ago before ATC recordings became mainstay on YouTube, there was an American pilot that declared an emergency at JFK and very firmly said "we are turning back and landing NOW. Get the aircraft OFF all runways".
He was low in fuel and also frustrated with Kennedy ATC because he declared "minimum fuel" earlier and was still getting vectored around. (I know "minimum fuel" is not an emergency and has a very precise meaning).
They must have been very close to running out. But it was a valuable lesson learned in speaking up before you get to that point.
I’m guessing that pilot had also been taught the lesson of Avianca 052, which crashed at JFK because the FO / captain did not explicitly declare a fuel emergency.
JFK ATC in particular has an enormous workload with many international flights, combined with direct, even conflictual at times, NY communication style. It puts the onus on the pilot for conveying the message to ATC, rather than ATC for extracting the message from the pilot.
> But it was a valuable lesson learned in speaking up before you get to that point.
I'm not sure it was a lesson learned per-se because the captain was merely doing his job as fundamentally defined.
A captain has ultimate responsibility for the aircraft.
However there is a side question in relation to your post...
When you say "declared an emergency" in your post, the more interesting question would be whether it was actually formally declared by the captain (i.e. "MAYDAY") or whether the captain was merely "working with" ATC at a lower level, maybe "PAN" or maybe just informal "prioritised".
If the captain DID declare "MAYDAY" earlier in the timeframe then yes, Kennedy would have a lot to answer for if they were spending excessive time vectoring around.
But if the captain did not formally declare and then came back later and started bossing Kennedy around, that would be a different set of questions, focused on the captain.
In the US, we don't typically call Mayday/PanPan (despite it being both allowable and more correct). Pilots literally say "N777DS declaring an emergency. Engine out/Low fuel/Birdstrike". The effect is that all emergencies are Mayday.
someone further down found the incident [1] I was referring to. It was 14 years ago, not 5 as I had initially thought. Curious to hear your take on it. Pilot said "if you don't give me this runway, I'm going to declare an emergency..." which I don't think is the most helpful thing to say. But there were definitely many swiss-cheese holes lining up that day.
But I'm truly surprised (in a bad way) people on the ground couldn't solve the situation earlier. The plane was in an emergency situation for hours, wtf.
Also, the airport density in the UK is high, they should have been diverted since before the first attempt, as it has happened to me and thousands of flights every single day around the world.
The incident investigation will surely focus on exactly those things. But: just like shipping aviation is at the mercy of the weather and even though the rules (which are written in plenty of blood) try to anticipate all of the ways in which things go wrong there is a line beyond which you are at risk. I've had one triple go-around in my life and it soured me on flying for a long time afterwards because I have written software to compute the amount of fuel required for a flight and I know how thin the margins are once you fail that third time. I am not going to get ahead of the investigation and speculate but I can think of at least five ways in which this could have happened, and I'm mostly curious about whether the root cause is one of those five or something completely different. Note that until there is weight on the wheels you don't actually know how much fuel remains in the tanks, there always is some uncertainty, to the pilots it may well have looked as if the tanks were already empty while they were still flying the plane. Those people must have been extremely stressed out on that final attempt to land.
That's one conclusion. But don't rule out a lot of other things that may have been a factor, for instance, they may have had a batch of bad fuel, they may have had less fuel to start with than they thought they had (this happens, it shouldn't but it does happen), the fuel indicators may have been off (you only know for sure after touch down), there may have been a leak, an engine may have been burning more than it should have. There are probably many others that I can't think of of the top off my head but there are a lot of reasons why the margins are as large as they are.
I read and agree with all those options being possible. Except the "they may have had a batch of bad fuel". How would that work in your thinking? I can imagine a bad batch of fuel leading to engine damage or flameout and many other things, but it is hard for me to imagine how a bad batch would lead to not enough fuel remaining in the tank.
If you have more water in the fuel than you think you do (there always is some due to condensation in the tanks) then you might be able to reach your destination but you'll be burning more 'fuel' than your original estimate would have you believe because there is less power per unit weight of (contaminated) fuel.
This is fairly common in GA and there are cases where it has happened in scheduled flights as well. That's why fuel sampling is common practice.
It's supposed to be an extremely low amount and the fuel pick-ups are placed such that it should never be a problem but there have been cases where water in the fuel caused problems, including at least one notorious crash where the cause was identified to be fuel contamination.
> One pilot who reviewed the log said: “Just imagine that whenever you land with less than 2T (2,000kg) of fuel left you start paying close attention to the situation. Less than 1.5T you are sweating. But (220kg) is as close to a fatal accident as possible.”
> The Boeing 737-800 had just 220kg of fuel left in its tanks when it finally landed, according to a picture of what appears to be a handwritten technical log. Pilots who examined the picture said this would be enough for just five or six minutes of flying.
For reference, passenger airlines immediately declare emergency if their planned flight path would put them under 30 minutes of fuel (at least in the US). Landing with 5 minutes remaining of fuel is very atypical
In commercial aviation (passenger/cargo), typically about half the take-off weight is fuel. That's not half the payload weight (pax + cargo + fuel), it's half the takeoff weight.
For a medium-range flight (say ~2000 mi / 3200 km) each passenger incurs somewhat more than their own weight in fuel.
Because the market responds to your behavior by slightly lowering the cost of flying to fill those seats, demand increases to match from slightly lower income people. Because they then organize their lives slightly more around cheap flights, it gets even harder to lower the impact of flying.
Paradoxically, rich people like us (you're a tech worker too...) flying more, because we're less sensitive to price, leave more room for pricing in carbon reduction strategies in the tickets/taxes. If you have more seats from the lower end of the market... you don't have as much flexibility in solutions.
Especially crazy considering the 737 is not a particularly large commercial aircraft.
40kg/minute is around 12 gallons (47 liters) of fuel per minute. Meanwhile a 777 burns around 42 gallons (160 liters) per minute. A 747 burns 63 gallons (240 liters) per minute - more than a gallon per second!
40kg of fuel per minute is a lot but airplanes carry a lot of people.
Web searches suggest a 737-800 gets about 0.5mpg at cruise. With 189 passengers in a one-class layout that’s 95mpg per passenger. With 162 in a two-class layout that’s 81mpg per passenger.
This is better than a single person in a car but four people in a Prius gets 50mpg * 4 = 200 mpg.
This is what vexes me about the lack of emphasis on highway self-driving. Everyone's obsessed with robo taxis.
An overnight trip that's automated could go at 40 mph and get seriously good gas mileage. I mean man with four people would probably get almost 100 miles per gallon.
And this would eliminate a lot of short-range flights
It should be a lot easier to implement than having to worry about a whole class of problems that robo taxis in cities have
The robo taxi links the last few miles to transit.
I recently travelled from my house in Seattle to my office in SF without ever getting in a car. I walked more in the airport than I did anywhere else.
Home -> Walk 11 min -> Metro Bus -> light rail -> SEA -> SF -> BART -> Walk 2 min to Hotel.
Next time I go down I’m going to take Amtrak. I couldn’t this time because it was full. In 2024 360,000 people rode that route on 730 trips for an average of about 500 people per trip. Looks like Amtrak gets between 0.6 and 2mpg. That’s 300mpg to 1000mpg per person which is better than a Prius’ 200mpg at 40mph.
Seattle to SF is 1019 miles. At 40mph that’s 25 hours, which is an hour slower than the Amtrak schedule.
The latest Captains Speaking podcast has an discussion about one of the hosts being in a similar situation: https://youtu.be/5ovlZ221tDQ
Fortunately, the flight left with extra fuel, because it was cheaper to carry excess from the origin airport than to buy it at the destination airport, so reserve fuel wasn't needed, but it was close. Also, there was lots of lightning.
I absolutely love insights like this into areas of the world I have no knowledge. Makes absolute sense in the modern world but also something I'd not think about
Trucking companies started adding this to their logistics about a decade ago as well. Once they had accurate fuel price information for most of the country they started telling their drivers precisely how much fuel to onboard at each stop.
As a naive person, I have a simple question - why would they even fly to an airport where there's 100mph winds? Wouldn't ATC know this and tell the flight way in advance to fly to a different destination?
Because the weather is very changeable. You may get a lull in the wind for a couple of mins, enough to land.
I've been on a couple of flights like that. Once where we did two attempts and landed on the 2nd, the other where we did 3 but the had to divert. Other planes were just managing to land in the winds before and after our attempts.
The other problem is (as I found out on that flight) that mass diversions are not good. The airport I diverted to in the UK had dozens of unexpected arrivals, late at night. There wasn't the ground staff to manage this so it took forever to get people off. It then was too full to accept any more landings, so further flights had to get diverted further and further away.
So, if you did a blanket must divert you'd end up with all the diversion airports full (even to flights that could have landed at their original airport) and a much more dangerous situation as your diversions are now in different countries.
This seems to be a case where the error was that the 2nd diversion was to another commercial/passenger airport. The situation after it was determined Edinburgh was a no-go was dire and making it to an airport like Manchester was a luxury they did not have safe fuel for.
It reminds me of a Transavia flight from Girona to Rotterdam that had to be diverted to Amsterdam back in 2015 (1 attempt at Rotterdam, decided to divert to Amsterdam, then 2 attempts in Amsterdam).
It was a particularly stormy weekend and it turns out from the article that they had 992kg of fuel left:
United Airlines Flight 173 ran out of fuel while circling Portland International Airport trying to troubleshoot a landing gear. Six more minutes of fuel could have helped the airliner to land in the Columbia river by the airport or belly land on the runway. The captain chose to keep troubleshooting and crashed just 6 miles away from the airport.
Had a 1 maybe 1.5h holding pattern in Oslo once in Ryanair where they hoped they could land in extreme snow. Then diverted in the end (surprise!). Happened in 2009 though. Joked they were very desperate to land at Oslo because they cant afford to divert.
You'll probably have to wait a while. Petter is pretty insistent on waiting for the full incident report so that he can be completely thorough and avoid speculating.
Sure, company dispatchers are usually part of the conversation, and in non-emergency diversions (i.e. the vast majority), they may suggest specific airports that would be more convenient for company logistics. But the final decision is always the pilots' - and once they've declared an emergency, more or less every single airfield, including military, becomes available to them.
We definitely involve the dispatcher in the diversion decision. Especially if it's an unplanned diversion, where the big-picture view the dispatcher has is very useful for us in our metal tube.
Unless they are in an emergency and are busy with aviating, they will coordinate with their dispatcher on diverting, even if only to verify that the weather at the intended alternate is still favorable. Per the FAA regulations, the PIC and the dispatcher have joint operational control over the flight. Of course, at the end of the day, only the pilots have their hands on the controls, so they can make the plane do what they want—but from a legal standpoint, the dispatcher and pilot-in-command have equal & shared responsibility for the safe operation of the flight.
I realize this is a UK carrier and was operating in the EU/UK, but for the most part, the rest of the world uses the US legal framework for aviation as a boilerplate for their own civil code. Yes, there are some differences, but these are usually minor and more of "differences in quantity" rather than "differences in kind". [Since the airplane was invented here the US had a head start on regulating civil aviation.]
Incident: Malta Air B738 at Prestwick, Edinburgh and Manchester on Oct 3rd 2025, landed below minimum fuel
By Simon Hradecky, created Sunday, Oct 5th 2025 14:39Z, last updated Friday, Oct 10th 2025 15:02Z
A Malta Air Boeing 737-800 on behalf of Ryanair, registration 9H-QBD performing flight FR-3418 from Pisa (Italy) to Prestwick,SC (UK), was on final approach to Prestwick's runway 20 when the crew went around due to weather. The aircraft entered a hold, then attempted a second approach to runway 20 about 30 minutes after the go around, but again needed to go around. The aircraft again entered a hold, about 10 minutes after entering the hold the crew decided to divert to Edinburgh,SC (UK) where the aircraft joined the final approach to runway 24 about one hour after the first go around but again went around. The aircraft subsequently diverted to Manchester,EN (UK) where the aircraft landed on runway 23R about 110 minutes after the first go around.
On Oct 5th 2025 The Aviation Herald received information that the aircraft landed below minimum fuel with just 220kg fuel (total, 100kg in left and 120 kg in right tank) remaining.
The aircraft returned to service about 13 hours after landing.
On Oct 10th 2025 the AAIB reported the occurrence was rated a serious incident and is being investigated.
A passenger reported after the first go around at Prestwick the crew announced, they would do another attempt to land at Prestwick, then divert to Manchester. Following the second go around the crew however announced they were now diverting to Edinburgh, only after the failed approach to Edinburgh the crew diverted to Manchester.
The headline is about the landing, but the issue here happened at takeoff. There were 100 mph winds at the destination and this was their 4th fallback attempt and their third airport. This flight should never have taken off, the risk of multiple diversions was easily predictable, but the flight took off headed toward an airport in dangerous conditions, got diverted to a second airport that was just as dangerous, then finally to a third where conditions were so bad other flights were being cancelled (https://uk.news.yahoo.com/storm-amy-brings-flight-chaos-2019...) and where it finally landed because it was either land at that airport or land somewhere that is not at all an airport. Once this flight was in the air, disaster was more or less inevitable and we lucked into a narrow eviting window.
This very recent Mentour documentary is extremely relevant, came to mind immediately. Multiple redirects due to bad weather, extreme "Get-there-itis" and eventually running out of fuel.
Great edutainment if you're feeling in the mood for that. If you're inpatient you can skip to 14 minutes, before that it's just backstory.
On the positive side, if they had made a crash landing with so little fuel, there would not likely have been a fiery explosion, and many more passengers would have survived than normal?
Air + fuel explodes just fine. You really don't want to crash an airliner. At landing speed the number of people dead will still be > 0 and the remainder has a good chance of being injured seriously.
This happened at landing speed (the airport is only a few hundred meters from the crash site) and the plane was at the end of its flight from Turkey, it did not catch fire. Still, 9 people perished and the remainder were all but one injured 11 of them seriously.
Dunno about "only" ... 99.99998% of flights kill 0% of their passengers. Even if "just" one passenger dies in an incident, your flight is already in the 0.00002th percentile for safety, very bad!
Yes, even though that is a harsh conclusion to make and for the families involved of course it doesn't matter at all. But as these come this was bad but still not nearly as bad as it could have been. They were about to cross one of the busiest highways in NL, another 100 meters and it would have been an entirely different story. The field they landed in is in the Haarlemmermeerpolder, so clay and it had just been plowed.
> and many more passengers would have survived than normal?
This[1] kind of crash landing is very rare (in that case there was no fire despite being immediately after take off, perhaps because of the cold). Normally an outcome like this is only reasonable to expect if you actually reach a runway despite being out of fuel. Like Gimli[2].
* enough reserve to waste some in traffic. On top of that
* enough reserve to find gas station. On top of that
* enough reserve to drive to neighbouring city for gas station. On top of that
* enough to cruise 30 minutes around that neighbouring city looking for other gas station in case the previous ones were closed. On top of that
* enough station to run around parking lot looking for space to park
Yes and no. I had this happen recently and looked into it.
My wife has been using my car, which is a Diesel Golf with a fuel capacity of 14.5 gallons. We set off driving one Saturday to visit my parents, and I noticed the fuel gauge was below empty already. By the time I got to the gas station, I put 14.3 gallons of fuel into it. I calculated that that works out to be about a cup and a half of fuel.
So once you hit empty on my car, you definitely have a ways you can drive still. I feel comfortable driving about 30+ miles, and it's never died on me. That puts it at no more than 1 gallon of fuel left in the car based on my experience (not scientific I know, but I've owned 2 of these cars, with about 190k total driven miles). It's a lot less than 10 liters from E to Dead on the roadside.
You shouldn't tempt fate with a diesel, or any direction injection car for that matter. The high pressure pump will shred itself very quickly as the diesel is used for lubrication.
> The pilots had been taking passengers from Pisa in Italy to Prestwick in Scotland on Friday evening, but wind speeds of up to 100mph meant they were unable to land.
> After three failed attempts to touch down, the pilots of Ryanair flight FR3418 issued a mayday emergency call and raced to Manchester, where the weather was calmer.
#1 - if Prestwick had wind speeds up to 100mph, then why the h*ll was the airport not closed down?
#2 - if the pilots had experienced conditions that dire during their first two landing attempts at Prestwick, then why the h*ll did they stick around for a third attempt?
EDIT: The article's a big vague, but it seems to have been 2 attempts at Prestwick, then 1 at Edinburgh, then the last-minute "oops, do I really want to die today?" decision to run to Manchester.
One of the problems with modern internet discourse is there is an implicit assumption that the problem of one country is automatically the problem of another country.
> Between overworked, understaffed ATC and undertrained pilots, I'm expecting some major disasters in the coming years.
Maybe in the US, but this story is based in Europe, each country maintains a regulated standard and there are no EU wide disruptions that have ever happened to the best of my knowledge. Also Ryanair don't travel transatlantic flights.
Three weeks ago in Nice, France it was a fraction of a second away from two A320s crashing [0] and possibly hundreds of deaths, similar to Tenerife disaster [1].
Investigation is ongoing and many factors are at play (bad weather, extra work for ATC due to that, confusing lighting of runways etc) but also, from French media reports, there used to be 15 people per shift 5y ago in Nice ATC, now there are just 12, and traffic is higher.
Many people left the profession during Covid and haven't been replaced.
Mistakes and disasters happen, unfortunately the safety we have while flying today has been written in blood, but there is no major understaffed ATC and undertrained pilots in general as mentioned.
15 down to 12 in 5 years with more traffic is not out of the question with advancements in technology but of course, if there is a report that shows understaffing then absolutely it should be addressed straight away and it will be, by the French government.
Why? Is ATC a problem in other countries than the US? Are they also under training pilots? If anything RyanAir with its flamboyant history of cost cutting (CEO always threatening to charge for use of the onboard lavatory) seems a more likely source than the flying infrastructure itself.
Ryanair has a very good safety history, among the highest in the world.
They make outrageous claims for publicity, and their customer experience is all about hidden extras and "gotcha" pricing, but I don't think they fuck around when it comes to safety.
They know that with their reputation they would be sunk if they did have a major incident.
> In 2012 and 2013 “Brandpunt Reporter” broadcasted a two episode TV investigation in which Ryanair pilots, speaking anonymously, raised concerns about the airline’s fuel policies and company culture. The pilots revealed that the company may be exerting pressure on them to minimize the amount of fuel they take on board – a practice which limits significantly the fuel costs for the company but could jeopardise safety in certain circumstances. The direct reasons for this broadcast were 3 emergency landings of Ryanair aircraft in Valencia Spain on the 26 July 2012, within a short timeframe due to low fuel levels.
What indication is there that our pilots are undertrained?
I am just a PPL, and that was not an easy thing to accomplish (most pilots complete 50% more hours than required before they are able to pass that test), but my impression is that western training standards for commercial pilots are incredibly high, and the safety record seems to back that up.
In the US, I think that's probably true especially using hours as a proxy for training.
The EU has shown us that you can safely have far fewer hours.
As a pilot I do think that nothing replaces butt in seat, but I also think that 1500 hours of instructing/aerial surveying/hour building is well into the diminished marginal returns area.
In this case, they likely had adequate fuel for, the usual eventualities but the weather in Scotland was particularly bad that night across the whole country (source: I live near Prestwick airport).
Either Edinburgh (on the east coast) or Prestwick (on the west coast) are ok (one or the other or both) but in this case neither was suitable so the nearest was Manchester - definitely an edge-case.
I don't know how much fuel they had, or if they could've fitted any more on the plane but it was unusual circumstances.
There was a military plane right behind it with the same issue that night too.
I've never heard of any of these problems with RyanAir. They treat you as less than cattle and generally their service is shit, but I'm not aware of RyanAir being unsafe.
Actually, in a quick check it seems the total fatality count for RyanAir is zero, with only two (on-fatal) major incidents (2008, 2021). That's seems a pretty good track record considering the amount of flights they do.
Waiting on full flight in Europe, good airport, for take off.
Pilot says over speaker : " We are delayed becuase FUEL guy got UPSET on tarmac and has QUIT. We know need someone ELSE to fill the plane with FUEL. " Said in a COMPLETELY nonchalant voice.
Immediately I get concerned, try not to think what cause a FUEL TECH to QUIT regarding THIS PLANE and fuel issue. Just close my eyes, relax.
2 minutes later pilot comes on intercom again "For some WEIRD reason, someone wants to get off the plane. Now we have to wait for ground crew to find his suitcasebecause of rules. How annoying.."
Plane waits for an hour on tarmac for BOTH passenger to get off and for FUEL to be finally "resolved".
Arrive eventually at destination.
Most of the trouble would have been avoided if the pilot had not sounded nonchalant about a "NON ISSUE about FUEL that a technician just QUIT OVER". I swear i even rememebr saying the statement with a hint of humour, like what on earth is the problem.
This is a true story, and the fact this incompetence happened to me, well I wouldnt have believed it otherwise.
That is very exceptional. I've written fuel estimation software for airliners (cargo, fortunately), and the number of rules regarding go-arounds, alternates and holding time resulted in there usually being quite a bit of fuel in the tanks on landing, by design. I've never heard of '6 minutes left' in practice where it wasn't a massive issue and the investigation into how this could have happened will make for interesting reading. A couple of notes: the wind and the time spent on the three go-arounds + what was necessary to get to the alternate may not be the whole story here, that's actually factored in before you even take off.
I'd be very wary to get ahead of the investigation and make speculative statements on how this could have happened, the one thing that I know for sure is that it shouldn't have happened, no matter what.
Naively as an outsider, this situation seems like everything worked as intended?
On a nominally 2h45m flight, they spent an extra 2 hours in the air, presumably doing doing fuel intensive altitude changing maneuvers, and were eventually able to land safely with their reserves almost exhausted.
I’m a little confused by what there is to investigate at all.
How much fuel should they have landed with?
As others have said, final fuel reserves are typically at least half an hour, and you shouldn't really be cutting into them. What if their first approach into MAN had led to another go around?
With a major storm heading north-easterly across the UK, the planning should have reasonably foreseen that an airport 56 miles east may also be unavailable, and should've further diverted prior to that point.
They likely used the majority of their final fuel reserve on the secondary diversion from EDI to MAN, presumably having planned to land at their alternate (EDI) around the time they reached the final fuel reserve.
Any CAA report into this, if there is one produced, is going to be interesting, because there's multiple people having made multiple decisions that led to this.
Suspect they were IFR. All your points stand. First time flying things with a jet engine, I was shocked how much more fuel gets burned at low altitude. It almost always works out better to max climb to altitude and descend than to fly low and level. On a small jet, things can get spicy fast when ATC route you around at 5000' for 15 minutes or so. Three aborted landings would gobble gas like crazy.
§ 91.167 Fuel requirements for flight in IFR conditions.
(a) No person may operate a civil aircraft in IFR conditions unless it carries enough fuel (considering weather reports and forecasts and weather conditions) to—
(1) Complete the flight to the first airport of intended landing;
(2) Except as provided in paragraph (b) of this section, fly from that airport to the alternate airport; and
(3) Fly after that for 45 minutes at normal cruising speed
Just reaching altitude again to make it to the first and later second alternate are mostly likely the biggest factors in the extra fuel consumption. That's very expensive.
The 30 min reserve is on top of the fuel needed to reach the alternate and do a landing there, so only the flight to the second alternate, plus the 2nd and 3rd landings at the initial destination would have cut into the reserve.
With 100mph winds I could easily see the 30 min reserve being eaten up by the flight from Edinburgh to Manchester. It's 178 miles! It takes a good 15-20 minutes to cross that distance when flying normally, add ascent & descent time and the landing pattern and you're easily at 24 minutes.
Edit: in other comments here, it seems like Edinburgh to Manchester is a 45 minute flight. So yeah, they could easily have been outside of reserves when they did the go-around at Edinburgh and still had only 6 minutes left at Manchester.
Yeah, although it depends what the alternate was in the flight plan. It may have been Manchester. Although I think its more likely it was Edinburgh, which in the circumstances was too optimistic. Too much concern about the minimal costs of fuel tankering to add a bit more gas? Or saving time by not refuelling?
Ive never flown on Ryanair and dont intend to.
You get that energy back on descent, no?
4 replies and 3 are dismissing even the idea..
Yes, you get "some" back, and its not negligible amount. Typical modern airliner can descend on 15-20:1, giving you over 150-200km (90-120mi) range from typical cruising altitude of 33 000 feet even with engines off. Most everyday descents are actually done by maintaining altitude as long as possible, and then iddling the engines fully for as long as clearance allows. (Ofc you then use engines as you geat nearer, because its safer to be a little low when stabilizing on approach, than a little high)
Thanks to turbofans(edited from turboprops) better efficiency + less drag at higher altitude its actually more fuel economical to command full thrust and gain altitude quickly, than slower climb, or maintaining altitude (which goes against our intuition from cars, where if you wanna get far, you never give full throttle).
But theres still some drag, so you dont get everything back, so you generally want to avoid murking in low altitudes as long as possible. Full thrust repeatedly at lowest altitudes (from failed go arounds) is the least economical part of flight, so you want to avoid those if possible. But its true that the altitude you gain is equivalent to "banking" the energy, just not all of it.
(1) this was a jet, not a turboprop
Edit: changed turbofan into turbprop, which is what I meant.
(2) fuel burned stays burned, you don't 'get it back'
(3) the altitude gained may have been adjusted to account for the low fuel situation
(4) the winds are a major factor here, far larger than the fact that 'what goes up must come down', something that is already taken into account when computing the fuel reserve in the first place.
(1) The turbofan category of jet engine seems to inspire a lot of very pretty animated technical diagrams—here’s one set from a German manufacturer [0]. Now if only we could convince Bartozs Ciechanowski to take on such a subject… [1]
(2) I know glider pilots who fly without any fuel at all, once aloft… sounds not unlike the 150-200km glide range that @MaxikCZ mentions at idle from cruising altitude.
[0] https://aeroreport.de/en/good-to-know/how-does-a-turbofan-en...
[1] e.g. https://ciechanow.ski/airfoil/
Aircraft that are designed as gliders are much lighter and thus have much longer glide range than aircraft that aren't. They're so lightweight that they can climb on thermals. A 737 is not going to be able to do that, but a regular glider can't fly at 400 knots.
> thus have much longer glide range
Im gonna be a little pedantic, but the weight has surprisingly small effect on glide range, actually none of the weight affect the range directly, its all from secondary effects.
The glide is given mainly by drag and lift (so body and wing geometry), correlated to certain speed. The weight isnt in the equation at all. What weight does, is increases the speed in which the aircraft achieves this maximum glide ratio, and in higher speed you have higher drag, which finally reduces the range.
Thats why many modern gliders have water tanks in wings, to increase the weight of the glider, moving planes speed of best glide ratio higher, allowing for more efficiency at higher speeds. Its worth it if the atmospheric condition provide strong lifts. Pilot can then dump the water in flight to reduce the wing load, allowing them to land with less speed, or just keep in the air longer as thermals get weaker in the afternoon/evening
(source, I used to be a glider pilot)
It should also be noted that gliders have crazy aspect ratios. Airliner wings are designed for completely different flight envelopes than gliders, it’s all a game of what you optimize for and what trade offs you are willing and/or required to make.
But of course that doesn’t mean that airliners can’t glide well, the Gimly Glider and Air Transat flight come to mind. But gliders can definitely beat an airliner in terms of performance.
You are, of course, correct, and thanks for clarifying.
Regarding the turbofan and [0], above...if you're communicating to a non-engineer (me), how does the design get to the point of such complexity? I would love to learn the design story behind such an incredibly complex piece of machinery.
I am being serious, if you cannot tell.
Re: (2): There's a difference between sailplanes and gliders. Sailplanes are gliders that can “soar”, i.e. gain altitude just from the air that is moving up for some reason. Your friends have licence that says „Sailplane Pilot Licence”, not „Glider”.
The distinction is less pronounced nowadays, because there is no mondern aircraft designed as gliders-but-not-sailplanes, but historically there were planes that fit this niche, mostly military transport of WW1 and WW2 vintage.
Passenger jets (with engines turned off) are relatively decent gliders, but incapable of soaring. So no, you can't get more that about 20:1 glide ratio no matter how good is the weather (for sailplanes).
Yes, sorry, meant to write turboprop.
The 737-800 uses CFM56-7 turbofan engines.
[1] https://en.wikipedia.org/wiki/CFM_International_CFM56#CFM56-...
No, you don’t magically get the fuel back. But you do get a lot of the _kinetic energy_ back, and that energy keeps you flying without having to burn yet more fuel. You burn a lot of fuel while climbing, but then hardly any at all while descending. And that descent might cover 100 miles across the ground.
1) Yea, sorry, turbofan, not turboprop nor a jet.
2) It stays burned, but the energy is banked in potential energy of the aircraft, namely in a form of altitude. If you run out of fuel 5 feet above ground, you dont get to fly far. When you run out of fuel 35000 feet above ground, you can still choose where to land from multiple options.
3) huh? I dont get what you trying to say, but: Its always more economical to climb, and the faster the better. Ofc you cant climb too high when you intend to attempt to land in 5-10 mins, but nontheless, every feet gained is "banked", and the aircraft is more economical to run the higher you are.
4) I am not saying the winds arent a factor, and in no way I was arguing about how fuel reserves are calculated. My only claim is that: yes, by spending more fuel to gain altitude, you can then "glide" down almost for free later. Its not 1:1, because of constant losses like drag, but its being compensated by higher engine efficiency and less drag at altitude, that its always worth it to climb if you can.
There was a flight that was low on fuel diverting to alternate between 2 islands. The pilot panicked and chose slower climb to intuitively save fuel. They had to ditch the plane in water because of it - if they initiated full climb, they would have made the jump.
1 - a turbofan is a subset of jet engine, and there are no 738s running anything other than a turbofan.
Actually, nothing in civil aviation that has a "jet engine" has used anything but a turbofan (or turboprop) since the early 70s with the exception of Concorde and some older business jets.
(Turboprops are jet engines, too, to be precise, with the jet of exhaust gases powering the propeller.)
> Turboprops are jet engines
They are certainly turbine engines, but I thought "jet" was reserved for those engines that propel the vehicle solely by their exhaust stream and bypass air. I am willing to be told I'm wrong, though.
Turbofans are by your own definition jet engines. It's just that the bypass air is much larger.
I think you meant turboprop there, but the distinction I notice is that one has all propulsive airflow inside the nacelle, and one does not.
Wow this has a lot of replies!
Yes, you get a lot of the energy back, BUT there is a huge problem!
Large airliners incur a LOT of additional drag to slow down while landing. Some of that is entirely intentional, some is less intentional.
It is highly preferred to deploy the landing gear before touching down. Failure to do so may lead to a hard landing and additional paperwork, so airlines do not allow the captain to exercise their own discretion.
Extending the flaps maintains lift at lower speed, and higher flap settings allow even lower speed. The highest flap setting generally also deploys leading edge slats.
If the wheels of the airliner touch down and detect the weight of the plane then spoilers kill the lift of the wings, air brakes fully deploy, as well as thrust reversers.
All of these things add drag, which uses up all that energy you've been converting.
The upshot is that each landing attempt uses a LOT of energy, and you have to use fuel to replenish that energy after every attempt.
In other words, yes you get it back, but only for one landing attempt.
As someone who has ridden a bike up a big hill, and then down it, I don't think you get it back.
That is perplexing. Of course you get the potential energy back. It turns into kinetic energy as you descend. That is why you need not pedal downhill, and often even need to brake to prevent the bike from speeding up too dangerously.
> often even need to brake to prevent the bike from speeding up too dangerously.
Indeed, which is what the airplane would have done on its way down to land. So it's more like riding the brakes on your way down the hill, and now at the bottom when you realize you need to abort the landing, you are at low speed and it's quite an exercise to get back uphill to try again
100%. You are correct on that. You can’t use your kinetic energy to go around after a landing attempt.
But not because “you don’t get the energy back”. (As recursive suggested about a downhill bike ride which is the part i am disagreeing with.) You do get it back, but because you want to land you bleed it away to drag. And once it is bled away you don’t have it anymore.
So we don’t disagree about the practical implications for flying. I’m disagreeing with recursive’s particular statement about downhill cycling and what it implies about the physics of the problem.
The glider guys would always suggest a forward slip. It's a lot of fun to do. It's not taught often enough during primary training for powered airplanes.
Yes, but that also doesn't get any energy back on descent, quite the opposite, that is "riding the brakes on your way down"
Imagine a hill with 500 feet of elevation descent, followed immediately by 500 feet of ascent. No curves.
If you coast all the way down the first part, you'll get about 20 feet up the other hill before you need to start pedaling. This is a direct analogy to "getting your energy back" by losing elevation.
That is exactly what a rollercoaster does and it doesn’t start “pedaling” after 20 feet. Of course real systems have losses and you can’t practically use all the energy.
But you don’t have to believe me. Look at the video of this glider doing an unlicensed airshow: https://youtu.be/QwK9wu8Cxeo?si=L-0Mfmu8wk1ZlQU7
It is a glider so it can’t “pedal”. You can see it steeply descending from 5:13 to 5:30 while it is speeding up and then the pilot picks up the nose and trades some of his speed for elevation again. And then he does it again around the 7 minutes mark.
You have two buckets of “water”. One bucket is kinetic energy and the other is potential energy. You can trade one for the other. You can also “lose” from the total volume of “water” due to drag (or friction in the case of the bike or roller coaster). Or you can add more “water” to your system by pedaling or thrusting with your engines. This is just simple physics 101. Also simple lived experience if you ever have the opportunity to fly an airplane.
The more water you put in your system the leakier your buckets get. Drag is not linear with speed. That was my point.
Just as with bikes, it will depend on how slow it is descending. On "right" trajectory engines could technically be basically idle, and you save fuel flying high so it might not be all that huge loss.
No, and you don't want it. You want to be on the ground and stopped. In the lowest energy state.
It's not currently feasible to harvest it into fuel. It's (very very nearly) all lost to drag, on purpose.
How? On descent you can trade some of your altitude (potential energy) for kinetic energy, but then you can’t land the plane. For descent on an approach you’re going from low energy to even lower energy. In emergencies and with enough runway you can futz around with this some, but wiggle room on an airliner is not great, negligible to what will be expended on a go around.
The problem isn’t getting the energy back, it’s doing so more slowly than gravity. Planes are somewhat limited in their ability to glide.
Some of it, but much is lost to drag. They do have to limit speed at all times.
Not really. While you have a large potential energy buildup at a higher altitude, you cannot "bank it" / "save it" on descent. There is no way to store it in batteries or convert it back into fuel.
One of the challenges of aeronautics is the efficient disposition of the potential energy without converting it all into kinetic energy (ie speed) so that the landing happens at an optimally low speed - thus giving you a chance to brake and slow down at the end.
Some of it. The air density is an important part of efficiency at higher altitudes, so every moment spent under like FL320 is wasted fuel.
So the entire climb "up", you are also wasting energy fighting the thick air. On the way back "down", that air again fights you, even though you are basically at idle thrust.
Your fuel reserves are calculated for cruise flight, so time spent doing low altitude flying is already at a disadvantage. "Two hours of reserves" is significantly less than that spent holding at a few thousand feet. Fuel efficiency while climbing is yet again dramatically worse
I thought a lot of airlines had rules to limit the number of attempts you could make at a single airfield in an attempt to prevent this exact kind of situation.
It sounds to me like they tried harder at their intended destination than maybe they should have, followed by going to an alternate airport that probably wasn’t a good choice in the first place, and then having to divert to the final airport where luckily they could land in time.
I'm not an aviation expert, but generally in safety engineering, safety buffers are not simply calculated as [normal situation] * [safety factor], but [worst case scenario] * [safety factor]
If you ever cut into your safety allowance, you've already fucked up. Your expected design criteria should account for all use cases, nominal or worst-case. The safety factor is there for safety, it is never intended to be used.
This is really helpful and I think I understand now.
The approach is basically “accounting for everything that might go wrong to the best of our experience, including problems arising from the complex interactions between the airplane and supporting ground systems and processes, this is how much fuel you need in the worst case scenario. And now lets add more to give us a cushion, and we will treat consumption of this last reserve as tantamount to a crash.”
Precisely.
This is exactly how it is in this case. Any consumption of the fuel reserve would result in an investigation, this is a very extreme case and it may even result in a change in the rules depending on the root cause.
Yeah idk people debating about this, if this justifiable then its all gucci and world can learn from such experience
Yes, exactly. The day it's normal to eat into the allowance is the day we start seeing planes falling out of sky for lack of fuel again. The only way to prevent that is to treat 30 min of fuel as seriously as you would 0 minutes.
"I’m a little confused by what there is to investigate at all."
You're confused why they should investigate how everyone on that flight came within minutes of dying?
Something about the fuel reserves, procedures, or execution was clearly flawed.
Although credit is due to fuel reserve policies considering they landed after two diversions and three go arounds.
And that’s why people shouldn’t trust the guardian.
Why not? It's a factual report stating that the AAIB has opened an investigation into a potentially dangerous incident. There's not any editorial bias evident. See other extensive comments as to why this is not just a case of "it landed, so what's the problem?".
Or did it work as intended? The plane had multiple failed landing attempts, was re-routed, and had enough fuel to land safely. While no one wants to cut it this close, this was not a normal flight.
I’m not an expert in this field, but it would seem that the weight of extra fuel would increase operating costs, so it’s is effectively insurance. How much extra fuel should be carried to account for unplanned events like this, while not carrying so much that it becomes cost prohibitive.
Fuel depletion is risky, but not that risky; see the Gimli Glider for a case much more dangerous than this, which still worked out amazingly well.
Edit: Here is the Wiki on incidents... https://en.wikipedia.org/wiki/Fuel_starvation_and_fuel_exhau...
That example is so well known due to how exceptional it was, especially how the pilots handled it. Robert Pearson, the captain, was a very experienced glider pilot. That's something that not many commercial pilots have.
There were also two factors in the landing, that allowed for this to happen. You're going to be coming in really fast for a landing, when gliding in a commercial jet, and you don't have access to your thrust reversers to slow it down. There was a repurposed runway, that they used to land, that just happened to have been used as a drag racing track and had a guard rail. They were able to slow down by scraping across that. It also just so happened the nose gear didn't deploy fully so scraping the nose of the plane against the ground also helped slow it down.
Needless to say it was a bunch of very fortunate events that allowed it to not end in disaster. In any case I would consider it very risky.
And even with all that scraping damage they were able to fly the plane out, repair it, and put it back in service. Amazing.
The "scraping helped slow it down" theory makes no sense to me. What do you think has a higher coefficient of friction - tire rubber on asphalt, metal on asphalt, or metal on metal?
I would hesitate to chalk it up to just theory, given it was in the NTSB report and they don't really mess around with throwing baseless stuff around. I'd be interested to take another look at it. They likely go into the material science and physics behind this very thing. They're usually filled with gems.
You also have to keep in mind, it wasn't just rubber against asphalt, it was rubber on a wheel that spins. I'm not sure if the front nose gear on a 767 has any brakes but even if it did, I can't imagine it would be sufficient at the speeds they were going.
I mistyped, as this was Canada it wouldn't be the NTSB but the Canadian equivalent at the time: Canadian Aviation Safety Board. The report is a good read.
They could have died. The nosewheel assembly being pushed up through the floor of the cockpit has killed more than one pilot.
Don't forget the surface area of contact...
Rubber likely grips much better than metal, however three wheels have massively lower surface area than the body of the plane, or even a small section of it like the head.
Of course we don't land tireless for other reasons (metal transfers heat exceptionally well unlike rubber, paint doesn't survive high speed impact, and it tends to deform upon impact with anything, making any future flights unsafe), but the fastest way to slow down if you don't care about safety or comfort would probably be to land tireless, if you could introduce some rotational spin, that might be faster (more force directed in multiple directions).
Also, on the note of "coefficient of friction", remember that this number is not just some innate property of a molecule - as the metal scratches the pavement and deforms, its coefficient of friction goes up as micro-deformities accrue.
You seem to be assuming those are "or" rather than "and"
Fuel depletion is stupendously risky, it is one of the most risky things that can happen to a jet. The only things more dangerous are fire and control systems failure.
The Gimli Glider was a case of many items of luck lining up.
Depends largely on the altitude when fuel runs out. If it runs out when they're at 4,000 ft and it's windy, it's probably game over.
I know you're trolling, but for anyone that hasn't heard of Gimli Glider, look it up or watch a documentary on youtube. The stars definitely aligned to make that happen.
Fuel depletion is _not that risky_ is an interesting take. But hey, it won Chapecoense its first and only Copa Sudamericana, so maybe it isn't that bad after all?
https://en.wikipedia.org/wiki/LaMia_Flight_2933
You could've read at least the Wikipedia page on how miraculous Gimli Glider was.
From "all engine failure is never expected and not covered in training" to "Pearson was an experienced glider pilot familiar with techniques rarely needed in commercial flights" to the amount of maneuvers they had to execute on a barely responding aircraft
Exactly, the takeaway from that saga is that extreme luck does happen, not that flying without fuel is perfectly safe.
They also happened to know about an old airport which was no longer active, but did not know about the concrete barrier in the middle.
And what happens if you're not at 40k feet when the fuel runs out?
Good thing that airliners spend so much time at altitude!
Especially while making landing attempts?
Well imagine they had to do a go-around on that landing. Go-arounds are extremely normal and might be done for a million reasons; your speed is wrong, your descent rate is wrong, your positioning is wrong, there's bad wind, there's an issue on the ground, etc etc etc. Six minutes of fuel is really not enough to be sure that you can do a go-around. So now, if ANY of those very normal everyday issues occurs, the pilot has to choose between two very bad options: doing a go-around with almost no fuel, or attempting a landing despite the issue. That's just way too close for comfort.
Aviation operates on a Swiss cheese model; the idea is that you want many many layers of safety (slices of cheese). Inevitably, every layer will have some holes, but with enough layers, you should still be safe; there won't be a hole that goes all the way through. In this case, they basically got down to their very last slice of cheese; it was just luck that the last layer held.
Depends if our goal is to have zero aircraft crashes. If the goal is zero, then for any given parameter, you have to define a margin of safety well before crash territory and treat breaching that margin as seriously as if there had been a crash.
Similarly planes are kept 5 nautical miles apart horizontally, and if they get closer than that, you guessed it - investigation. Ofc planes could come within inches and everyone could live, but if we normalize flying within inches, the we are also normalizing zero safety margin, turning small minor inevitable human failings into catastrophe death & destruction. As an example, planes communicate with ATC over the radio and are given explicit instructions - turn left 20 degrees, fly heading 140 etc. From time to time these instructions are misunderstood and have to be corrected. At 5nm separation everyone involved has plenty of time to notice that something was missed/garbled/misinterpreted etc and correct. At 1 inch separation, there's no such time. Any mistake is fatal, even though in theory you are safe when separated by 1 inch.
TBC an investigation doesn't mean investigating the pilots in order to assign blame, it means investigating the entire aviation system that led up to the breach. The pilot's actions / inaction will certainly be part of that, but the goal is to ask, "How could this have been avoided, and ask how every part of the system that we have some control or influence over might have contributed to the outcome"
We shouldn't aim for 0 crashes due to low fuel though. How many deaths does carrying around 3x fuel than what you reasonably need contribute to via extra pollution?
We should aim for 1 every 10-100 years or something reasonable like that.
We should account for deaths from pollution, but if we are going to do that, we should be willing to do that for 99% of aviation fuel that has nothing to do with reserves & safety margins, in addition to fuel used to drive cars.
Any regulation short of "carry infinite fuel" will be a trade-off, and entail some risk and anyone involved in setting these knows that. Zero may not be our actual target or even possible, but it is a useful aspiration to ensure that everyone is pulling in the right direction.
We dont aim for 0. Zero means dont fly. one in every 100 years globally for all flights would be very safe.
If you cut into the final reserve, it’s a full-blown emergency requiring a mayday call.
This should not happen. So what’s there to investigate? How it was allowed to happen, and how to prevent it from happening again.
EDIT: it’s a mayday even earlier than that. It’s a mayday once the pilots know that they WILL land with less than the final reserve.
If they have to touch and go, how long would it take until they get the plane around for another approach? In fact, you might not get as far as that touch and go and have to go around. You need some margin for all of these eventualities. The likelihood is low that these happen, but they have to be accounted for.
Sure, but the flight was a lot longer than planed. How much extra do we need. They declared an emergency, and thus put themselves at the front of the line. They had 6 more minutes to do that touch and go around if that happened, and since they were already in a low fuel emergency they get priority and so there is enough time to do that if they needed. (edit - as others have noted, 6 minutes with high error bars, so they could have only had 30 seconds left which is not enough)
They landed safely, that is what is important. There is great cost to have extra fuel on board, you need enough, but it doesn't look to me like more was needed. Unless an investigation determines that this emergency would happen often on that route - even then it seems like they should have been told to land in France or someplace long before they got to their intended destination to discover landing was impossible.
> They had 6 more minutes to do that touch and go around if that happened
6 minutes is way out of the comfort zone. They might not have made it in that case.
Correct, article says they landed with 220kg which is around 6 minutes of average fuel burn over an entire flight - bit less at cruise, a hell of a lot more at takeoff/climb.
So I don't think 220kg is enough to do a go-around in a 737 (well, a go-around would've been initiated with a bit more than 220kg in the tank - they burned some taxing to the gate - but you get my point.) I've read around 2,300kg for takeoff and climb on a normal flight in a 737-8. A go-around is going to use close to that, it's a full power takeoff but a much shorter climb phase up to whatever procedure is set for the airport and then what ATC tells you.
I just flew 172s but even with those little things we were told, your reserve is never to be used.
These people came very, very close to a disaster. Fortunately they had as much luck left as they did fuel.
I agree, well out of comfort zones. However to my reading multiple different things went wrong to get to this point.
That could be. We just don't know right now, but your intuition may well be correct, even if there is a single root cause there could very well be multiple contributory causes.
They failed to land at two airports before the third. I can't say if they made the right decisions but that already is two failures.
Go arounds are not failures.
They are expected situations, but still a failure of the original plan.
With 6 minutes left everyone could have died if anything went wrong with the final landing, even a gust of wind could have ended everybody's life.
Could have, but pilots practice no fuel landings all the time (in simulators). If they can get to ground that is "level enough" nobody dies. It is not something you ever want to see in the real world (and in the real world people often do die when it happens), but it isn't automating people die.
I don't think that's all that true for airliners. Pilots definitely practice for engine-out scenarios during all levels of training up to the airlines, but the ability of a plane the size of a 737 to safely land on anything but a runway is...limited. And if you're low, slow, and trying to go around, that's not a lot of time to glide to ground that is "level enough".
i didn't mean to imply no runway landings. Landing on grass is questionable. They would practice water landings though
Those landings are practiced from a reasonable altitude.
How much extra do you need? Enough that a pilot/crew doing their job properly will never run out of fuel and crash.
So yes they will do an "investigation". It's not a criminal investigation. It's to understand the circumstances, the choices, the procedures, and the execution that ended with a plane dangerously close to running out of fuel.
This will determine if there were mistakes made, or the reserve formula needs to be adjusted, or both.
Don't tell me about cost, just stop. Let MAGA-Air accept some plane deaths to have cheap fares.
Surely the issue is more that they decided to make so many attempts to land local. There should be a max level of attempts.
There is a lot of pressure on pilots to land local. But 3 go-arounds happens, not often, but it does.
Perhaps that decision needs to be removed from the airline and there needs to be an independent decision maker there.
Pilots are ultimately responsible for the aircraft, that's pretty much set in stone but if ATC would tell them to divert they would unless there already was an emergency.
Naively as an outsider, this situation seems like everything worked as intended?
I don't remember all of the rules off the top of my head, but if you are ever landing with less than 30 minutes of fuel, something has gone seriously wrong. You are required to take off with sufficient fuel to fly to your destination, hold for a period of time, attempt a landing, fly to your alternate, and land all with 30 minutes remaining. If you are ever in a situation where you may not meet these conditions, you are required to divert immediately. In choosing your alternate, you consider weather conditions along with many other factors. This was, without question, a serious emergency.
From the very brief description in the article, I would say they should have diverted to Manchester at least 25 minutes sooner than they did. I will include the GP's caution, however:
I'd be very wary to get ahead of the investigation and make speculative statements on how this could have happened, the one thing that I know for sure is that it shouldn't have happened, no matter what.
This reminds of discussions following the Fukushima disaster where one commenter claimed that it wasn't a design flaw, because it was an extraordinary circumstance. I found this appalling, because I do not at all think that was the risk profile that was sold to the public; I think people believed that it was supposed to be designed to safely survive 1000-year earthquakes and the tsunamis that they create.
Likewise, I think that the flying public is lead to believe fuel exhaustion is so rare that when airlines are compliant with regulations, no such disasters across all flights across all carriers will occur during your lifetime.
It's also a communication problem, because labels like "100-year/1000-year event" are easily misunderstood.
* they're derived from an estimated probability of the event (independently) happening each year. It doesn't mean that it won't happen for n years. The probability is the same every year.
* the probabilities are estimates, trying to predict extreme outliers. Usually from less than 100s of years of data, using sparse records that may have never recorded a single outlier.
* years = 1/annual_probability ends up giving large time spans for small probabilities. It means that uncertainty between 0.00001% and 0.00002% looks "off by 500 years".
https://practical.engineering/blog/2025/9/16/an-engineers-pe...
I'm sure we can all remember at least one person in any situation who will say something we find memorably awful.
My understanding is that they shouldn't have spent that much time in the air (not intended as a guess for the cause). The margin is there for situations where you can't land earlier, not the margin for scheduling the landing. There is margin for expected potential delays, they were in the other margin that should never be used except in true emergencies.
Oh I think I see; so is the question not “why did they land with so little fuel”, but more like “why did it take so long to decide to redirect to a known-safe airport”?
Possibly. Or 'why did your fuel readings deviate from what was actually in the tanks' or 'why did we leave with less fuel than we thought we did' and so on. There are so many variables here speculation is completely pointless. All we know is that something went wrong, that it almost led to a crash and that it involves an airline with a very good record when it comes to things like this.
Low fuel happens, but this is (very) exceptional.
I don't know. As the parent said, I'd be careful with guessing the root cause right now. They should not have been this low even if diverted due to weather.
By asking such a question you understand the need for an investigation
Might not be about fuel but about why they even tried instead of diverting earlier.
Might even be 100% done by the book but book needs changing (tho I doubt that, it's not exactly first case of "a lot of bad weather")
Only issue I see is that should there have been stricter rules to diverting way earlier. If winds were such as to make landing harder. Would just directly going somewhere else been the correct choice to force.
It also sounds like they went to an alternate airport they probably shouldn’t have bothered with.
Well, if you know you're pretty low on fuel, you are likely to pick an airport where the weather is good, rather than risking three more missed approaches at a closer one where the weather is probably also bad.
Of course, Manchester is also a Ryanair base. There are two Ryanair bases closer to Prestwick (Edinburgh and Newcastle), but maybe the weather was bad there too? If the fuel situation was so dire, questions might be asked during the investigation why they didn't pick a closer airport with good weather that wasn't a Ryanair base (if one existed), but ultimately it's the pilots' decision to fly a bit further to an airport they are familiar with, and second guessing them with the benefit of hindsight is probably not a good idea...
This is likely one of the questions the investigation will focus on.
One of those YouTube channels where a professional pilot evaluates flying incidents had a similar incident when the pilot started yelling at the tower when they tried to make him go around again. He essentially said he would declare an emergency if he didn’t hear different instructions. I think he had 10-15 minutes when he touched down.
One of the things the reserve is for is if the plane immediately in front of you fucks up the runway, you now have to divert to the next airport. You need at least enough fuel to get there and for the tower to shove everyone else out of the way so you can make an emergency landing.
There are other reasons someone could abort a landing and have to go around again, besides debris in the runway. And sometimes two of them can happen consecutively.
In the case I’m referencing, it was pointed out that p the pilot made things worse by going faster than he was told to fly, using up fuel and also making him too close to a previous plane which forced him to go around the previous time, so it wasn’t all the tower.
> I’m a little confused by what there is to investigate at all.
So because the safety margin still worked while down to near vapors we should conclude there's nothing to learn for the future to reduce the risk of similar incidents?
That's certainly... a take.
>I’m a little confused by what there is to investigate at all.
One of the most important aspects of taking safety seriously is that you do not just investigate things which had an impact, but that you proactively investigate near misses (as was the case here) and even potential incidents.
A plane with 6 minutes of fuel left is always a risk to every person on board and potentially others if an emergency landing becomes the only option.
Indeed that is the definition of a "aviation incident" where there was a risk of injury or damage. If there is actual injury or damage it becomes an "accident".
The investigations into incidents aren't usually particularly long or noteworthy and often the corrective action will be to brief X on dangers of Y, or some manner of bulletin distributed to operators.
Flight from Edinburgh to Manchester is just a bit more than 1 hour, so after trying 2 landings, diverting to Edinburgh (15-20 minutes flight), 1 more landing attempt, well, you get very close to 2 hours.
I felt like that seems a little long from EDI to MAN (after all, EDI to LHR is typically a flight time of under an hour!), so:
https://globe.adsbexchange.com/?icao=4d2256&lat=54.720&lon=-... is the track of this flight.
Went around at EDI at about 19:10Z, landed at about 19:51Z, so about a 41 minute flight.
Right, I probably got the information for flight time as seen by a passenger on a ticket, not for a plane already flying. Thanks!
I think a more insightful answer is how often is it acceptable for the reserves to actually be cut into. If this was happening often, then there’s a likelihood of a future disaster. As it is there is 1 isolated case that still ended with a positive outcome. I think it almost adds support for the current reserve levels to be pretty dialed-in.
Officially: never. Unofficially, a minute or two would be cause for concern and the regulators would most likely be showing an interest. The airline may have a higher margin than the official one. This is exceptional, they were within the margin of error on readout and the pilots must have known that. It's one thing to know you have half an hour of fuel give-or-take in the tank it is another to know that give-or-take you are running on fumes.
The answer is 'never' as the reserves are only added for worse-than-worst case scenario, i.e. in this case something went literally unimaginably (as of then) wrong.
I dont know but maybe they should have diverted sooner. Maybe an hour into the flight?
6 min, is empty, 6 min is purely theoretical, 6 min would not clear for ground handling or a test start, or a fuel system check,6 min would not do a go around. will interesting to see if they release info about what the real amount of fuel left is, and an authorative discussion on how much useable flight time was there. did they actualy make the taxi to the terminal?, or run out on the apron?
I think the article says that someone saw 220kg written on a log - that's about 6 minutes worth at cruise. So yeah, it's zero basically.
Yes. There is another comment above making light of the 6 minutes as if another go-around was still an option, that is a ridiculous take. They were going to bring that plane in and land it no matter what on this last run, otherwise they'd crash for sure. 6 minutes may not even be within the margin of readout.
30min+
Yes, I believe this is correct for this model aircraft.
ideally, enough to divert to another airport, in the off chance something happens, like a pending emergency at point post.
If you get shot, but had a bullet proof vest on, and hence didn’t die, technically everything worked as intended.
Personally, I’d still want to figure out why I got shot and work on making sure that didn’t happen again.
Especially if you basically got shot multiple times (for an analogy in this case).
Imagine you're standing on a balcony and discover that the supports are cracked almost all the way through.
Do you shrug and say, that's why they have a safety factor, everything worked as intended? Or do you say, holy crap, I nearly died, how did this happen?
The purpose of the safety factor is to save you if things go badly wrong. The fact that it did its job doesn't mean things didn't go badly wrong. If you don't address what happened then you no longer have a safety factor.
Whether it can be prevented in the future. Should planes fly with even more reserve fuel? It's possible. Or maybe different ways of selecting alternate landing sites?
It may even be the answer is "no, everything went as well as it possibly could have, and adding more reserve fuel to every flight would be unacceptably wasteful, so oh well", but at a minimum they'll probably recommend even more fuel on certain flights into risky weather.
At what point should they investigate?
0 minutes?
-1 minutes?
Anything less than 60 minutes would be looked at by the airline, anything less than the legally required amount (30 minutes for a jet of this type iirc) will result in a very serious investigation. Note that for slower aircraft (for instance a turbo-prop) the time requirement goes up not down because they may have to spend more time in the air to reach an alternate (or secondary alternate, if things are really bad, like what happened here).
Really? Equally as an outsider - it feels like one "go-around" and you're fucked.
I have known former air traffic controllers that won't fly certain airlines because of a notorious habit some have for queue jumping by claiming they're low on fuel. If they are low on fuel is something else, but in any case when the ATCs have noticed a pattern then something is up.
This situation sounds a lot less nefarious, but it does also sound like they should have rerouted earlier.
Since there's a lot of confusion in the comments below I'm going to hijack one of the top comments to make a couple points clear from the article and FlightRadar24 data: [1]
They did reroute earlier. It was 2 failed attempts on Prestwick (Glasgow), 45 minutes in the landing pattern, then they diverted to Edinburgh (15 minute flight), a failed attempt at Edinburgh (~5-10 minutes), and then they diverted to Manchester (45 minute flight) and landed successfully there. Likely they hit their reserve just as the Edinburgh landing failed and decided to fly to Manchester, with clearer skies, rather than risk another failure in their reserve.
IMHO the only questionable pilot decision here is to divert to Edinburgh rather than Manchester immediately. But this is somewhat understandable: first of all, dropping the passengers off at Edinburgh (an hour drive from Glasgow) is significantly less costly and less inconvenient than dropping them at Manchester (an overnight bus ride). Second, if the Edinburgh landing had been successful they would not have eaten into their reserve and no investigation would've been needed. Third, the Monday-morning quarterbacking could've easily gone the other direction if they had diverted to Manchester ("Why did you choose an airport 178 miles away and risk eating into your fuel reserve when Edinburgh was right there?")
[1] https://www.flightradar24.com/data/flights/fr3418#3c7f91f4
> IMHO the only questionable pilot decision here is to divert to Edinburgh rather than Manchester immediately. But this is somewhat understandable: first of all, dropping the passengers off at Edinburgh (an hour drive from Glasgow) is significantly less costly and less inconvenient than dropping them at Manchester (an overnight bus ride).
Yeah, as someone who knows next to nothing about airlines, but has seen these type of decisions in businesses, this was the thing that stood out to me. This is all pure speculation of course, but I'd be curious how clear it was that Edinburgh would also have a high risk of being unsuccessful and whether the pilots felt any pressure to try that anyway. E.g. are there consequences for pilots who cause delays for passengers?
> E.g. are there consequences for pilots who cause delays for passengers?
I'd imagine heavily depends on how often that happens vs other pilots on same route. Tho I'd imagine consequences are "here is more training".
To me the 45 minutes in the landing pattern also seems questionable.
At the point they left it, they still had about an hour and 20 minutes of fuel remaining, with an alternate airport 20 minutes away. They had not declared an emergency, so they were in with any other traffic waiting for takeoff and landing. (Which does make me wonder, did any other planes try to land at Prestwick at the time and how did they fair?)
Quick note that Preswick is not really Glasgow (35 miles away) and Glasgow has its own airport which presumably was also affected by the same weather so they couldn't divert to that. Between the Scottish lowlands (where they had already tried all the commercial airports) and anywhere else, Manchester is about the closest option.
As someone totally ignorant of British airports, a Google maps search for "airports northern england" shows Teesside, Carlisle, and Newcastle all significantly closer to Edinburgh than Manchester. Are these not places where a 737 under emergency could land? Or was the weather also bad there?
Carlisle is small (and not currently licensed for public use) - not an ideal place to drop a 737 if there's a choice. It's also not that far from Prestwick so may have had similar weather. Newcastle and Teesside are both on the East coast and likely to be affected by similar weather to Edinburgh given the storm coming in from the North East. The next closest will be Manchester or Leeds/Bradford, with Manchester being larger, closer to where passengers want to go (Glasgow) and further away from the storm.
There's precedent for this kind of situation to generate quite extensive investigations. An incident in 2017 where a flight from the Isle of Man to Belfast was unable to land in a storm, diverted back to the IOM, then landed in unsafe weather conditions because of insufficient fuel to divert again got a 48 page report[0], safety recommendations, and the airline being banned from the UK.
[0]: https://assets.publishing.service.gov.uk/media/5a82ede440f0b...
Leeds/Bradford is on a plateau and can get affected by wind.
> Or was the weather also bad there?
That's likely, these places are not very far apart, and weather systems that cause 100mph winds don't tend to be small. And presumably if you have at most one landing attempt remaining you don't want to be taking any more chances.
Carlisle is a small domestic airport. The other two might have been affected by the storm as well. The weather was bad enough to down trees in London.
so the pilot fucked up either way right????
when you piece it together like that its a close call and maybe a hindsight but its understandable if pilot do this
Claiming you're low when you are not is going to cause a major headache for the PIC, they're going to have to write that up and they may well be investigated. If it turns out they were lying they would likely find out that that is a career limiting move and if it happens too often then that too should result in consequences. The main reason is that your fake emergency may cause someone else to have a real one.
What’s the mechanism for them to get caught?
When you declare a fuel emergency or even urgency, there's often follow up to figure out why (mechanical issue? problem with dispatch? problem with flying technique? exceptional weather condition that could be forecast better? etc). And there is plenty of data in aviation to know what happened.
Dispatch knows how much fuel they say they put in.
Your flight time, speeds, and profile are known.
ACARS may be reporting fuel use throughout the flight.
etc, etc, etc.
Random spot checks. Every day at every airport some of these will get verified. Also, the next pilot would have to be willing to cover for you because they are going to have to falsify their records to make your trick invisible. You record the amount of fuel in the tank when you take command of the aircraft, the amount of fuel that was loaded and from that it is trivial to compute how much was left the last time it landed.
Lets say a plane crew claims low fuel.
The pilot in charge has to file a writeup.
When someone accepts the writeup, there's a random chance it's selected for followup. If/when they discover there was enough fuel, it will affect the career(s) of person(s) involved.
First, generally, people don't like having to do paperwork, and especially don't like doing paperwork to help you land a little quicker.
While one time may not be a fireable offense, you will find you career affected in the number of ways people can find to be uncooperative with you, or not support you when you attempt to advance your career within the company.
Developing a habit would lead your interlocutors to escalate the situation, which would lead to discipline up to and including the company firing person(s) involved.
Which airlines? I feel like if this is an issue we should be naming names.
RyanAir is famously one of them.
Edit: I was recalling articles claiming the company purposely fueling less than other airlines in order to increase their rate of claims for priority landing to have a better "on time" statistics.
This forum post disputes that: https://aviation.stackexchange.com/questions/38501/is-it-tru...
also carrying less fuel does save on fuel usage
No way.
Having attended meetings at ICAO I can also tell you many details of various aviation incidents, including their existence, are covered by some secret classification. This fact being disclosed caused most of the attendees to lose all hope in the rest of the proceedings. To their credit the FAA reps on that occasion were by far the most reasonable gov representatives in the room, and the FAA are one of the major voices pushing for greater transparency on it.
Which specific civil aviation incidents are covered by some secret classification?
> Which specific civil aviation incidents are covered by some secret classification?
You would have to have secret clearance to know which ones
It's cool, I have Top Secret Level 3 (Omega Sector) clearance so you can go ahead and tell me.
It’s generous of the classifying authority to send to the ICAO meeting somebody both appropriately credentialed to know about the information in question, and willing to talk coyly about it. Did these additional incidents inform the policy discussions at the meetings you attended?
It's funny you say that, because the way it happened was it was blurted out by a diplomat from a certain country, at which point most of the regulators facepalmed and all of those of us from outside were having the same reaction as many here.
The whole subject of discussion prior to this was efforts to improve data sharing wrt incidents.
Kinda surprised there's no data link for that sort of telemetry so that you don't necessarily have to take the pilot's word for it.
Second guessing a pilot saying they have a problem is a really bad idea. ATC second guessing an emergency is a really bad idea. Making a pilot explain why they're actually low on fuel, despite whatever some computer is saying, instead of focusing on flying the plane is a really, really bad idea.
Also, that sort of telemetry does exist for most major airlines, however it goes via satellite to the airline not the ATC.
I am not saying you are wrong, but both Type I and Type II errors are problematic. What if the pilot is wrong?
Korean Air Flight 801 could have used someone 2nd guessing a pilot. They didn't until they were almost dead and then it was too late. Not 2nd guessing the pilot was a really really bad idea.
If the pilot is wrong you hope the copilot or someone else on the crew picks up on the error and corrects it. If they’re both wrong, or if they don’t feel empowered to challenge the pilot like in Korean Air 801, everyone is usually fucked.
ATC doesn’t have the kind of situational awareness or manpower to fix these kinds of problems the vast majority of the time. It only seems like they could have done something after the fact when the disaster has already happened and hindsight activates.
Like the GP said, ATC second guessing pilots is a really, really bad idea. A few incidents doesn’t change that.
That specific incident resulted in a lot of changes to the rulebook and some very specific notes about training in terms of cultural differences.
> Korean Air Flight 801 could have used someone 2nd guessing a pilot.
...yeah, the second pilot. And in this case, also flight engineer.
IIRC The problem was pretty much aside from errors the cultural issues with pilots, the "lower ranks" wouldn't dare to be assertive to seniority and just voiced the issues they saw without doing anything.
I expect that they take the pilot's word in case of a rare situation [1] and then make the fill a ton of paparwork to try to solve the main cause and also discourage lies.
[1] In one case someone mixed imperial and metric unix, and instead of $something-kilograms, they put only $something-pounds of fuel.
This incident is known as the Gimli Glider and was actually due to multiple failures before the pound-kilogram issue (and the backdrop of Canada's then-recent metrication) even became relevant: https://en.wikipedia.org/wiki/Gimli_Glider
Would that be more reliable than just ensuring there are consequences for lying?
Perhaps. If the pilot knows that the ATC can see he's full of it, he might be less likely to lie.
Those who still do can be grounded and be moved into management or take up a career in politics.
I’m surprised the “fuel on board” isn’t something communicated via transponder considering previous low fuel emergencies/crashes.
As a rule airline pilots don't lie about this stuff. They take safety pretty seriously.
Putting a theory of "you shouldn't trust pilots" into ATC breaks the entire system.
It is a system built out of very regulated parts, very professional people, and tight controls.
Pilots are encouraged to be very forward and proactive about fuel situations because of https://en.wikipedia.org/wiki/Avianca_Flight_052
Minimum fuel requirements are calculated as "Time of fuel for cruise to certain points", which is usually good enough, but if an Airport is stupid busy, or has bad wind patterns, just a couple go-arounds will chew through your fuel way faster than the regulation expects.
Turbofan engines are also dramatically less efficient at low altitude than high altitude cruise. So holding at low altitudes because a congested airport is dealing with traffic will chew through your reserves much faster than you expect.
Ryanair flies short hops to congested airports. They will have relatively low reserves, and you should expect them to run into "Hey we are low on fuel" more often than international flights for example.
"It is a system built out of very regulated parts, very professional people, and tight controls."
Locally, this is true. Globally, not so much. I remember my friend's vivid description of a flight taken in Nepal. It was absolutely wild.
"claiming they're low on fuel"
It is almost fascinating how humans will stoop to dishonesty even in banal situations - and not just any humans, but pilots, who should be subject to at least some vetting.
Maybe planes should be retrofitted as to transmit their actual fuel state including a qualified assessment in minutes to the ATC. Not just because of the cheaters, but also to warn the ATC in the rare case that some plane crew isn't very assertive about their dwindling fuel, or hasn't noticed the problem.
It would make prioritizing the queue a bit more neutral.
If I designed such a system from scratch, "remaining fuel" would be part of my telemetry.
>If I designed such a system from scratch, "remaining fuel" would be part of my telemetry.
Careful what you wish for. I'd rather people skip the queue by pretending to be low on fuel than people skip the queue by actually being low on fuel.
You mean that ATC would abuse their position by making planes circle as long as they have some fuel left?
And the reason why those fuel reserves exist is to be a guard band allowing situations like this to happen without flames, wreckage, and death.
Having worked with many US airline pilots over the years, this is also why they are so proud to be unionized. Sure, senior pilots make as much as some FAANG developers, but the union is also there so that management doesn't get bright ideas about things like cutting fuel reserves to cut costs without the union telling them to stuff it.
Management can't cut fuel reserves, not because the pilots are unionized but because there are some very strict rules about these fuel estimations prior to take off and margins be damned. And those rules are exactly there because otherwise this kind of incident would happen far more frequently. But it's regulation that is the backstop here, not the pilots.
The point is that the unions are there to allow the pilots to advocate for all kinds of safety-of-flight related things like fuel reserves, crew rest, and so forth that management would be happy to cut to save money. And to do so without fear of retaliation.
And if you don't think the airlines would love to lobby Congress about the regulatory backstop, well . . .
As I wrote elsewhere in this thread I actually wrote software to estimate the amount of fuel a jet should load to comply with the rules. This was commissioned by the airline and they were scared shitless that they would ever be found to be in breach of the regulations on this aspect. It is one of those red lines that you really do not wish to cross. There are other aspects of flight where you are right but this particular one is different.
The main reason why airlines would like to take the least amount of fuel is because it immediately increases payload capacity and thus flight efficiency. This being a cut-throat market there is a serious incentive to cut it as fine as possible. So the regulations around this particular issue are incredibly strict: you have to have a certain amount of fuel left upon landing, you have to write up truthfully how much you still had left and you will be investigated without fail if you cut into the reserve. The good thing about unions here is that they help to make sure that pilots know they are safe reporting truthfully because the airlines can not retaliate if they would pressure the pilot to not report an incident (which all pilots would normally definitely do). So they're a factor, but it is the regulator that writes the rules here and they are super strict about this.
And that's immediately why the calculation of the estimate becomes so important: you now have 30 minutes (or 45, depending) of deadweight + the deadweight for two alternates and an x amount of time in a holding pattern, plus up to three go-arounds. That really adds up, so you have to do your best to get the calculation as close as possible to what it will be in practice without ever cutting into that reserve.
It took me the better part of a year and massive amount of learning to write a small amount of code + associated tests to pass certification. It also taught me more about software engineering (as opposed to development) than anything I did up to that point in time and it made me very wary about our normal software development practices.
I think the literal fear of death _might_ be motivation enough for pilots to advocate for safety? And if they want to fire you, would you want to work for them anyways?
> I think the literal fear of death _might_ be motivation enough for pilots to advocate for safety?
You'd think, but individual humans are very very bad at estimating risk, and in toxic group and work situations, humans will often take on increased personal risk rather than risk conflict. I.e., they will value group conformity over their own safety ... especially if their paycheck is involved. Fear of death is not nearly as powerful as robust regulation and unions.
Famously, this fact is also why no one drives recklessly and no one has lost any limbs with power tools.
The alternative to employment is death. Many people are willing to take a possible chance of dying to avert a certainty of dying.
Regulations are paper. Who enforces the behaviour, of whether to take off or not, on a windy night in central Italy?
Of course the pilots are the backstop, and the unions are theirs, so they can make necessary calls the money doesn't like.
The union is a nice backstop for issues around the edges that come up with corporate, but the real backstop is the pilots’ licensing. By making them directly responsible for the plane as PIC, it gives them leverage over their employer that few other professions have. AIR-21 gives them significant protection from retaliation and the ASRS is confidential. ALPA helps them navigate that mess if it comes to it, but that’s the real legal backing that pilots have.
Same thing happens with Professional Engineers regardless of whether they are employed or work as independent consultants/firms. They’re legally responsible for the bridges and other infrastructure they sign off on with laws protecting them from employers and clients.
(I fully support the ALPA and other unions, I just don’t think it plays as significant a role in following regulations as you claim)
...that regulation is text in a database. It can be changed capriciously at any moment, like they often are.
It takes people with ideas and a willingness to put pressure in the right places to be sure that sane policies prevail.
I think it's pretty obvious that as time moves forward, we need to rely on "regulations" less. The root and history of the word in the political context is to make things regular. But state actions increasingly bring irregularity to the world.
It seems absolutely fair to say that, in this situation, the people - the pilots in particular, but also cabin crews, ATCs, engineers, and their unions, are the backstop worth observing and celebrating.
If you land with less fuel than the legal minimum you are going to have a lot of explaining to do, there will be an investigation and you, the pilot and the airline will get enough headache from it that you will make bloody sure it does not happen again. The pilot(s) may not be able to fly until that investigation has run its course, the airline may get fined or warned if this is the first time it happened. In an extreme case the pilots may lose their license.
> It seems absolutely fair to say that, in this situation, the people - the pilots in particular, but also cabin crews, ATCs, engineers, and their unions, are the backstop worth observing and celebrating.
I will hold off on that conclusion until the report is in. There are so many possible root causes here that speculation is completely useless, and celebrations would be premature.
My apologies - I didn't mean to speculate about this incident in particular, but about the general role of so-called "regulation"; I thought it was unfair to minimize the role of the people and unions compared to the (in my view, comparatively flimsy) legislation.
I think the thing that's being pointed out as overlooked when praising the employees and the unions, is the regulators, who are the people who play a very large part in making sure that the regulations are enforced. The regulations are just text in a database, but it's the regulators who actually make it happen. A pilot who wants to push back against a beancounter cutting corners has a union and a regulatory agency to back them up.
> Sure, senior pilots make as much as some FAANG developers
That's a funny way to phrase it. I'd probably go the other way and say "sure, FAANG developers make as much as some pilots..."
Those pilots have hundreds of lives on the line every day.
Yes. I think the average bus and train driver is completely underappreciated as well and they have a massive responsibility too. I know I could not do their jobs, it would weigh on me too much.
Those FAANG devs have milions of (social) lives on the line, though. Every day.
Is this a joke?
> I'd be very wary to get ahead of the investigation and make speculative statements on how this could have happened, the one thing that I know for sure is that it shouldn't have happened, no matter what.
Just watch Juan Browne, he usually turns out pretty good in analyzing the mishaps. He didn’t upload anything for Manchester yet but will probably soon: https://youtube.com/@blancolirio
I remember this stuff being a bigger story for a short moment x years ago, where low cost carriers (it might have been Ryanair then, too) routinely flew with unreasonably small amounts of "backup" fuel and had to declare emergencies in order to get on the ground safely.
I guess they're trying it again now that the whole thing had blown over.
Pretty obviously not the case here if you read the article.
Yeah, again, I’m going to wait for the Mentour Pilot analysis on this one.
I'm just curious, is this hard on the fuel pumps? I've always been told to not run gas down in your car because the pumps will get hot.
The pumps are fuel cooled, but it's designed such that the pumps remain in the fuel even in a low fuel situation.
Yeah, to give some idea, I believe the technical term that would have been radioed from the pilot in this situation would have been "mayday fuel."
> it shouldn't have happened, no matter what
You hear that a lot, with Ryanair stories.
Sounds like a great airline!
Ryanair has an impeccable safety record.
How many go-arounds and alternates are usually accounted for? Assuming EU, high-airport density etc, typical 2h flight.
Does the estimation change depending on weather forecast, season of the year etc?
3 go arounds + 2 hours in a holding pattern should result in at least 45 to 60 minutes left in the tanks after landing. Depending on the kind of aircraft that can be a pretty impressive amount of fuel.
> Does the estimation change depending on weather forecast, season of the year etc?
Yes. There are many factors that go into this including trade winds (which vary quite a bit seasonally and which can make a huge difference), time of day, altitude of the various legs, route flown, weather, distance to alternates, altitude of the place of departure and altitude of the place where you are landing, weight of the aircraft, engine type, engine hours since last overhaul, weight of passengers, luggage and cargo, angle-of-attack and so on. The software I wrote was a couple of thousand lines just to output a single number and 10x as much code for tests, and it was just one module in a much larger pre-flight application.
I can only imagine how the test suite looks like. Wild.
This made me think about the fuel itself: is aviation fuel globally standardised and the same quality in every single airport in the world?
The test suite was much larger than the code. It took ages to get it certified, the calculations had to be correct to the last significant digit on reference problems to prove that the algorithms had been implemented correctly. This caused a bit of a headache because the floating point library that I used turned out to be slightly different than the one from the benchmark.
There are three different kinds of jet fuel and all are produced to strict standards, and then there are allowances for ppm water contamination (very low, to ensure the fuel system will never freeze at altitude or in freezing weather on the ground or at lower altitude).
Do forecasted storms go into the fuel estimate formulas?
Yes. Even not forecasted storms in the form of a probability of wind at low altitude when the engines are at their least efficient. And tradewinds at altitude, which are quite variable as well.
This honestly makes me think that we're missing a trick if an option for this sort of circumstance can't be "send a military fuel tanker up to refuel them in air" as a last ditch emergency measure (which IMO you would've triggered in this exact scenario).
The argument in favor is simply that we need in air refueling for the military, but justifying all that expenditure is a lot easier if it's dual use technology.
Very insightful, thanks. Glad everything was ok.
All I had to contribute was to ask if they were trying to hypermile or something?
const estimateFuel = (distanceInKms, litersPerKm) => distanceInKms * litersPerKm;
I don't even know what I'm talking about, but you at least forgot to account for headwinds and differing drag amounts at different altitudes/speeds.
The big one is the trade winds. Those can really kill your efficiency on long distance flights.
Yes it was a bit of humor, sad it didn’t land.
Under FAA rules this was a screwup. [edit: see my own reply] (However, the rules are subtle, so they can be partially forgiven.) However, I'm not only a dispatcher but also a philosophy BA, so I've found a good way to explain it.
Your reserve fuel (the "extra" fuel over what the actual flight burn) can of course be used (hello, that's what it's there for) but—and here's the rub—you can never plan on using it.
That is to say, in this case, when they missed their first or second approach, they CANNOT say, "We'll use our reserve fuel and make another go at it" because that would be intentionally planning to burn your reserve.
You may only dip into your reserve when you have no other choice. In this case, when the only fuel they had left was reserve, they are obligated by law to proceed to the alternate airport, which clearly they did not do [correction: they did do the proper thing; see my 2nd reply below]. No bueno.
[this is a slight simplification (minor details omitted for brevity) but the kernel of the issue is properly described]
Update: OK, if *Edinburgh* was their alternate and they missed there and were then forced to bugout for Manchester, that's then an example of when reserve is OK to be burned. (The 'slight simplification' I omitted was unpacking how the alternate fuel plays into the process, but here, that was a key part of the series of events.) That's what I get for not reading TFA first :-/
Not really, you should have enough fuel to make it to multiple alternatives or make emergency landing somewhere else. You should never burn that last 45 mins unless you want to make the news and file a lot of paperwork.
The regs are quite specific on if and when we need an alternate, which is weather dependent, and what your fuel requirements are. And we don't really have the idea of "multiple alternatives", but I guess it's implied by the additional reserve - what us Americans call a reserve or the Europeans call "final reserve". In case you're curious, we use the TAF (termimal area forecast) to determine if we need an alternate, and use a 1,2,3 rule which is 1 hour before and 1 hour after arrival time we need ceilings of at least 2000 ft and 3 statute miles of horizontal visibility.
Er.. and maybe crash and kill yourself, all your passengers and crew and people on the ground.
I just had my paid-for LLM summarize the events.
The sequence was [depart Pisa => Prestwick (2 missed approaches) => proceed to Edinburgh (1 missed); declare Mayday fuel => proceed to Manchester (land on first attempt)]
I'm curious why you did that? It's not a very complicated sequence. The whole point of engaging in a discussion here is to think about the issues raised and offer a point of view while incorporating other perspectives into yours. You've spent your money to bypass the whole intent of this site; akin to you being hungry then sending someone else to a restaurant for you so you can later read their review of the food.
EDIT and you of most of the commenters here, with your industry background, are better placed to offer an opinion!
> It's not a very complicated sequence.
For me, it was. I have trouble forming a mental model of itineraries so I’m grateful for the summary.
I think you missed the point.
Presenting information in different ways is useful (and the method of display can offer informational insights itself). And for different users it might help parse larger connections. And by using the LLM to summarize just that one facet of the problem (itinerary and sequence) and sharing it here, they’ve contributed in a meaningful way. It may not have warranted a response. But it added to overall understanding of the problem space to help facilitate discussion. And they did well enough by citing that the info came from an LLM. They didn’t bypass the intent of the site. They added to it and fell right in line with that intent.
Okay that's fair.
I had no issue with the contribution itself, the route summary is helpful.
> And they did well enough by citing that the info came from an LLM.
In terms of acknowledging AI contribution, you're damned if you do, damned if you don't. Here it's sidetracked a discussion; but transparency is better than otherwise I suppose. Perhaps it just boils down to taste - and I don't like it.
Anyway, you made me think!
With all due respect, you are the one that sidetracked the discussion, not the person that acknowledged AI
Thanks, I appreciate it!
Even though I’ve read the entire article, I found it very difficult to mentally visualize and ended up not noticing that there were three destination airports involved.
> That is to say, in this case, when they missed their first or second approach, they CANNOT say, "We'll use our reserve fuel and make another go at it" because that would be intentionally planning to burn your reserve.
Is that what happened? That's not in the article, what's the source?
And other comments here are saying the third attempt was in Edinburgh, so they were already trying to land anywhere possible by the third attempt.
At what point are you saying they chose to plan on using reserves when they still had any option for landing without reserves?
OP didn’t have the full picture. They’ve offered appropriate edits/updates
> Under FAA rules this was a screwup
An oversight I'm sure they can fix ;-)
FAA as a yardstick? Hm
If you're into your reserves you should declare an emergency immediately to get priority in air traffic sequencing and control.
Pilots may be organizationally disincentivized when making this decision.
It's required when using your reserve under EASA to declare Mayday Fuel.
"Under FAA rules this was a screwup."
Not necessarily. And I get that you've caveated yourself with an edit and a reply etc, but lets assume that you're not hedging for the moment.
They carried required reserves on departure. Multiple approaches thwarted by extreme unforseen weather. They declared Mayday Fuel, which is mandatory under EASA regulations, when reserve fuel use became unnavoidable. They diverted to the nearest suitable airport.
Landing with 220kg is close, but within bounds of a declared fuel emergency.
Crew decision to declare Mayday and divert was proper airmanship, not negligence.
Yes, reserve fuel may not be planned for. But it may be used. It's there for a reason. Your accusation doesn't account for dynamic evolving weather and realtime decision making.
I'm an instrument rated pilot and an advanced ground instructor under FAA and I fly IMC in bad weather as single pilot IFR around the pacific northwest and colorado.
This is the right answer.
Was this good/bad? Idk Room for improvement? Maybe? Clearer direction with the benefit of hindsight? Maybe. but the majority of the sentiment in the responses is coming from people not type rated in a 737.
in what way do FAA rules apply to operators doing a European to UK flight in an airline that doesn't operate in the US?
Similar philosophies but with differences. e.g. FAA reserve requirements is destination + alternate + 45 mins reserve. EASA is destination + alternate + final reserve which is 30 mins holding for jets and 45 mins for pistons IIRC. But in both cases it's that idea of a destination, an alternatite, and additional. And then there's the requirements around whether you need an alternate, etc.
I was wondering that too. I've taken it to mean "if this situation had happened in the Americas..." as the most generous interpretation I can make.
Looks like they tried two attempts to land in Prestwick over two hours, then flew to Edinburgh and made one aborted landing, then finally went to Manchester.
What a nerve wracking experience for those pilots. I wonder if on the final attempt they knew they had to force it down no matter what.
Per the FlightRadar24 logs, it looks like only about 45min was wasted over Prestwick, not 2hrs. First approach was around 18:06, and they're breaking off to head for Edinburgh by about 18:51.
If there's considered to be a mistake here though, I'm guessing it's going to be spending too long before committing to the initial diversion.
Without knowing the weather they were seeing at the time, seems hard to say if they should have gone for a closer 2nd alternate than Manchester.
I don't think we know yet when min fuel was declared. At that point, they will be resequenced. Then we need to know when mayday fuel was declared. It sounds pretty odd, like perhaps there were multiple simultaneous situations and the crew did not have adequate information.
Assuming it wasn't just luck, it seems impressive they managed to maximize their (landing attempts/fuel reserves) ratio like that.
It is a requirement [1] to land with 45 minutes of fuel remaining, if the pilots go under that, it is considered an incident. As soon as estimated landing fuel goes under the limit, the flight needs to declare an emergency (as was done in this case).
[1]: https://www.ecfr.gov/current/title-14/chapter-I/subchapter-F... is the US rule, EASA has a similar rule.
Exactly. This will have a lot of consequences.
They got within a hair of crashing, there is nothing impressive about this. 30 minutes, ok, you still get written up but this is cutting it way too fine.
> this is cutting it way too fine.
Either this is true, or this is why there’s a 45 minute reserve requirement. There were three failed landing attempts in two airports prior to the successful landing, and they spent almost as much time attempting to land as the scheduled flight took.
Seems like this was exactly the scenario it was designed for?
I would imagine 6 min fuel left was designed for something extreme. Maybe involving damage to aircraft limiting where it can land etc. Or extreme weather event such had high winds affecting all airports within 500 miles.
No, this is what should never happen. I wrote fuel estimation software for cargo 747's and the one thing I would have never ever wanted to read is that an airliner of the company I worked for had landed with too little fuel.
About 5 years ago before ATC recordings became mainstay on YouTube, there was an American pilot that declared an emergency at JFK and very firmly said "we are turning back and landing NOW. Get the aircraft OFF all runways".
He was low in fuel and also frustrated with Kennedy ATC because he declared "minimum fuel" earlier and was still getting vectored around. (I know "minimum fuel" is not an emergency and has a very precise meaning).
They must have been very close to running out. But it was a valuable lesson learned in speaking up before you get to that point.
I’m guessing that pilot had also been taught the lesson of Avianca 052, which crashed at JFK because the FO / captain did not explicitly declare a fuel emergency.
JFK ATC in particular has an enormous workload with many international flights, combined with direct, even conflictual at times, NY communication style. It puts the onus on the pilot for conveying the message to ATC, rather than ATC for extracting the message from the pilot.
You might be thinking of https://www.youtube.com/watch?v=-sQuHnrJu1I
For comparison, this is what can happen when the pilots are not that assertive https://en.wikipedia.org/wiki/Avianca_Flight_052
this was it, thanks for finding it. I didn't realize it happened 14 years ago
> But it was a valuable lesson learned in speaking up before you get to that point.
I'm not sure it was a lesson learned per-se because the captain was merely doing his job as fundamentally defined.
A captain has ultimate responsibility for the aircraft.
However there is a side question in relation to your post...
When you say "declared an emergency" in your post, the more interesting question would be whether it was actually formally declared by the captain (i.e. "MAYDAY") or whether the captain was merely "working with" ATC at a lower level, maybe "PAN" or maybe just informal "prioritised".
If the captain DID declare "MAYDAY" earlier in the timeframe then yes, Kennedy would have a lot to answer for if they were spending excessive time vectoring around.
But if the captain did not formally declare and then came back later and started bossing Kennedy around, that would be a different set of questions, focused on the captain.
The word Mayday is not required to declare an emergency. Pan pan still indicates an emergency. And neither phraseology is required as long as the intent is clear, see https://www.faa.gov/air_traffic/publications/atpubs/atc_html...
In fact, it doesn’t even need to be the pilots who declare an emergency https://hsi.arc.nasa.gov/flightcognition/Publications/non_EA...
In the US, we don't typically call Mayday/PanPan (despite it being both allowable and more correct). Pilots literally say "N777DS declaring an emergency. Engine out/Low fuel/Birdstrike". The effect is that all emergencies are Mayday.
someone further down found the incident [1] I was referring to. It was 14 years ago, not 5 as I had initially thought. Curious to hear your take on it. Pilot said "if you don't give me this runway, I'm going to declare an emergency..." which I don't think is the most helpful thing to say. But there were definitely many swiss-cheese holes lining up that day.
1. https://www.youtube.com/watch?v=-sQuHnrJu1I
Context: because of bad weather.
But I'm truly surprised (in a bad way) people on the ground couldn't solve the situation earlier. The plane was in an emergency situation for hours, wtf.
Also, the airport density in the UK is high, they should have been diverted since before the first attempt, as it has happened to me and thousands of flights every single day around the world.
The incident investigation will surely focus on exactly those things. But: just like shipping aviation is at the mercy of the weather and even though the rules (which are written in plenty of blood) try to anticipate all of the ways in which things go wrong there is a line beyond which you are at risk. I've had one triple go-around in my life and it soured me on flying for a long time afterwards because I have written software to compute the amount of fuel required for a flight and I know how thin the margins are once you fail that third time. I am not going to get ahead of the investigation and speculate but I can think of at least five ways in which this could have happened, and I'm mostly curious about whether the root cause is one of those five or something completely different. Note that until there is weight on the wheels you don't actually know how much fuel remains in the tanks, there always is some uncertainty, to the pilots it may well have looked as if the tanks were already empty while they were still flying the plane. Those people must have been extremely stressed out on that final attempt to land.
Armchair quarterbacking it, but it was human error. They should have diverted sooner and been more aware of the weather.
Edit: there might also be part of Ryanair culture that contributed, but that's speculation.
That's one conclusion. But don't rule out a lot of other things that may have been a factor, for instance, they may have had a batch of bad fuel, they may have had less fuel to start with than they thought they had (this happens, it shouldn't but it does happen), the fuel indicators may have been off (you only know for sure after touch down), there may have been a leak, an engine may have been burning more than it should have. There are probably many others that I can't think of of the top off my head but there are a lot of reasons why the margins are as large as they are.
Those are all possibilities, but
https://www.flightaware.com/live/flight/RYR3418/history/2025...
They had at least an extra hour of fuel, and they landed at the third airport they tried.
Yes, that's how it should be. Something went badly wrong here. The big question is what.
I read and agree with all those options being possible. Except the "they may have had a batch of bad fuel". How would that work in your thinking? I can imagine a bad batch of fuel leading to engine damage or flameout and many other things, but it is hard for me to imagine how a bad batch would lead to not enough fuel remaining in the tank.
If you have more water in the fuel than you think you do (there always is some due to condensation in the tanks) then you might be able to reach your destination but you'll be burning more 'fuel' than your original estimate would have you believe because there is less power per unit weight of (contaminated) fuel.
This is fairly common in GA and there are cases where it has happened in scheduled flights as well. That's why fuel sampling is common practice.
Interesting. That makes sense. Thank you for the explanation!
It's supposed to be an extremely low amount and the fuel pick-ups are placed such that it should never be a problem but there have been cases where water in the fuel caused problems, including at least one notorious crash where the cause was identified to be fuel contamination.
> One pilot who reviewed the log said: “Just imagine that whenever you land with less than 2T (2,000kg) of fuel left you start paying close attention to the situation. Less than 1.5T you are sweating. But (220kg) is as close to a fatal accident as possible.”
Now that is range anxiety.
For anyone interested, here is the flight playback:
https://fr24.com/data/flights/fr3418#3c7f91f4
Sub required.
I can wait for the Pete the Irish Pilot’s take though.
this one is available - https://www.flightaware.com/live/flight/RYR3418/history/2025...
> The Boeing 737-800 had just 220kg of fuel left in its tanks when it finally landed, according to a picture of what appears to be a handwritten technical log. Pilots who examined the picture said this would be enough for just five or six minutes of flying.
For reference, passenger airlines immediately declare emergency if their planned flight path would put them under 30 minutes of fuel (at least in the US). Landing with 5 minutes remaining of fuel is very atypical
> the Boeing 737-800 had just 220kg of fuel left in its tanks... enough for just five or six minutes of flying
Maybe I'm just unaware, but it's crazy to me that these planes burn 40 kilograms of jet fuel per minute.
I don’t think that’s so much? A car burns 1 liter to travel 15 kilometer’ish, and carries 4 people.
An airplane burns 40 liters to travel 15 kilometers too (900 kph), but carries 160 people.
That’s about 40x more than the car, so the fuel economy per passenger is about the same.
Of course jet fuel is probably a bit more polluting, but it’s still interesting how close it is.
The greenhouse effects of flying is about 3-5x the effect of just burning the fuel.
In commercial aviation (passenger/cargo), typically about half the take-off weight is fuel. That's not half the payload weight (pax + cargo + fuel), it's half the takeoff weight.
For a medium-range flight (say ~2000 mi / 3200 km) each passenger incurs somewhat more than their own weight in fuel.
Yeah, when people say "flying has a high carbon footprint", they're not kidding. It's really quite massive.
I don't fly any more.
Want to bake your noodle?
Because the market responds to your behavior by slightly lowering the cost of flying to fill those seats, demand increases to match from slightly lower income people. Because they then organize their lives slightly more around cheap flights, it gets even harder to lower the impact of flying.
Paradoxically, rich people like us (you're a tech worker too...) flying more, because we're less sensitive to price, leave more room for pricing in carbon reduction strategies in the tickets/taxes. If you have more seats from the lower end of the market... you don't have as much flexibility in solutions.
Which is a strong argument for a carbon tax on (fossil) fuels. Indexed to consumption over greenhouse gas emissions targets.
Taxes are one way to make markets internalise externalities.
Hi, I'm the choir you're preaching to
> leave more room for pricing in carbon reduction strategies in the tickets/taxes
that is politically driven and has nothing to do with whether rich or poor bums are on seats.
Don't look up the carbon footprint of driving then. That is even higher in comparison to most passenger flights.
The data on https://ourworldindata.org/travel-carbon-footprint disagrees, do you have a source?
Each of the four F1 engines on the Saturn V burned 1.8 metric tonnes of liquid oxygen and 0.8 tonnes of rocket fuel every second.
> 40 kilograms of jet fuel per minute.
That is going to vary considerably between cruising and ascending.
That is why some people avoid flying for environmental reasons. Planes use crazy amounts of fuel.
Especially crazy considering the 737 is not a particularly large commercial aircraft.
40kg/minute is around 12 gallons (47 liters) of fuel per minute. Meanwhile a 777 burns around 42 gallons (160 liters) per minute. A 747 burns 63 gallons (240 liters) per minute - more than a gallon per second!
Is that at cruising altitude?
40kg of fuel per minute is a lot but airplanes carry a lot of people.
Web searches suggest a 737-800 gets about 0.5mpg at cruise. With 189 passengers in a one-class layout that’s 95mpg per passenger. With 162 in a two-class layout that’s 81mpg per passenger.
This is better than a single person in a car but four people in a Prius gets 50mpg * 4 = 200 mpg.
This is what vexes me about the lack of emphasis on highway self-driving. Everyone's obsessed with robo taxis.
An overnight trip that's automated could go at 40 mph and get seriously good gas mileage. I mean man with four people would probably get almost 100 miles per gallon.
And this would eliminate a lot of short-range flights
It should be a lot easier to implement than having to worry about a whole class of problems that robo taxis in cities have
Sounds like a train.
The robo taxi links the last few miles to transit.
I recently travelled from my house in Seattle to my office in SF without ever getting in a car. I walked more in the airport than I did anywhere else.
Home -> Walk 11 min -> Metro Bus -> light rail -> SEA -> SF -> BART -> Walk 2 min to Hotel.
Next time I go down I’m going to take Amtrak. I couldn’t this time because it was full. In 2024 360,000 people rode that route on 730 trips for an average of about 500 people per trip. Looks like Amtrak gets between 0.6 and 2mpg. That’s 300mpg to 1000mpg per person which is better than a Prius’ 200mpg at 40mph.
Seattle to SF is 1019 miles. At 40mph that’s 25 hours, which is an hour slower than the Amtrak schedule.
Yes. Electric self driving cars are why I am not too concerned about all the tunnel and highway building. They are train tracks of the future.
Train tracks are the train tracks of the future.
Trains are far more efficient than cars, especially at scale.
Possibly related, but not definite, this apparently has happened before with Ryan Air.
https://avherald.com/h?article=454af355
https://www.independent.co.uk/travel/news-and-advice/exclusi...
These were not definitive but it did raise concerns due to the budget nature of the airline.
The latest Captains Speaking podcast has an discussion about one of the hosts being in a similar situation: https://youtu.be/5ovlZ221tDQ
Fortunately, the flight left with extra fuel, because it was cheaper to carry excess from the origin airport than to buy it at the destination airport, so reserve fuel wasn't needed, but it was close. Also, there was lots of lightning.
I absolutely love insights like this into areas of the world I have no knowledge. Makes absolute sense in the modern world but also something I'd not think about
Trucking companies started adding this to their logistics about a decade ago as well. Once they had accurate fuel price information for most of the country they started telling their drivers precisely how much fuel to onboard at each stop.
Yeah makes sense. Similar to my electric car now I think about it. Optimises charges based on capacity and price.
As a naive person, I have a simple question - why would they even fly to an airport where there's 100mph winds? Wouldn't ATC know this and tell the flight way in advance to fly to a different destination?
Because the weather is very changeable. You may get a lull in the wind for a couple of mins, enough to land.
I've been on a couple of flights like that. Once where we did two attempts and landed on the 2nd, the other where we did 3 but the had to divert. Other planes were just managing to land in the winds before and after our attempts.
The other problem is (as I found out on that flight) that mass diversions are not good. The airport I diverted to in the UK had dozens of unexpected arrivals, late at night. There wasn't the ground staff to manage this so it took forever to get people off. It then was too full to accept any more landings, so further flights had to get diverted further and further away.
So, if you did a blanket must divert you'd end up with all the diversion airports full (even to flights that could have landed at their original airport) and a much more dangerous situation as your diversions are now in different countries.
Forecasts are based on multiple weather simulation runs.
It's a often good working gamble that you will pick a short period of weather that is within your operational limits.
Commercial pilots don't have "personal limits". It's defined by their airplane and/or companies constraints.
This seems to be a case where the error was that the 2nd diversion was to another commercial/passenger airport. The situation after it was determined Edinburgh was a no-go was dire and making it to an airport like Manchester was a luxury they did not have safe fuel for.
The only real question for the inquiry is how the decision was made to divert to Edinburgh and whether that was a reasonable decision at the time.
It reminds me of a Transavia flight from Girona to Rotterdam that had to be diverted to Amsterdam back in 2015 (1 attempt at Rotterdam, decided to divert to Amsterdam, then 2 attempts in Amsterdam).
It was a particularly stormy weekend and it turns out from the article that they had 992kg of fuel left:
https://avherald.com/h?article=489d4c3f
Massive respect for pilots and the job they do.
United Airlines Flight 173 ran out of fuel while circling Portland International Airport trying to troubleshoot a landing gear. Six more minutes of fuel could have helped the airliner to land in the Columbia river by the airport or belly land on the runway. The captain chose to keep troubleshooting and crashed just 6 miles away from the airport.
https://en.wikipedia.org/wiki/United_Airlines_Flight_173
Had a 1 maybe 1.5h holding pattern in Oslo once in Ryanair where they hoped they could land in extreme snow. Then diverted in the end (surprise!). Happened in 2009 though. Joked they were very desperate to land at Oslo because they cant afford to divert.
I look forward to watching this one on Mentour Pilot
You'll probably have to wait a while. Petter is pretty insistent on waiting for the full incident report so that he can be completely thorough and avoid speculating.
Given it's Ryanair I doubt we will see it, still hope so (Peter works for them)
Can anyone say whether airline pilots make each diversion decision solely based on their own information and judgment, or do they loop in the company?
Sure, company dispatchers are usually part of the conversation, and in non-emergency diversions (i.e. the vast majority), they may suggest specific airports that would be more convenient for company logistics. But the final decision is always the pilots' - and once they've declared an emergency, more or less every single airfield, including military, becomes available to them.
Airline captain here.
We definitely involve the dispatcher in the diversion decision. Especially if it's an unplanned diversion, where the big-picture view the dispatcher has is very useful for us in our metal tube.
Unless they are in an emergency and are busy with aviating, they will coordinate with their dispatcher on diverting, even if only to verify that the weather at the intended alternate is still favorable. Per the FAA regulations, the PIC and the dispatcher have joint operational control over the flight. Of course, at the end of the day, only the pilots have their hands on the controls, so they can make the plane do what they want—but from a legal standpoint, the dispatcher and pilot-in-command have equal & shared responsibility for the safe operation of the flight.
I realize this is a UK carrier and was operating in the EU/UK, but for the most part, the rest of the world uses the US legal framework for aviation as a boilerplate for their own civil code. Yes, there are some differences, but these are usually minor and more of "differences in quantity" rather than "differences in kind". [Since the airplane was invented here the US had a head start on regulating civil aviation.]
Even fighter jets have more fuel reserves when they land. This is insane.
Looks like the emergency reserve management worked?
Better links
https://avherald.com/h?article=52dfe5d7&opt=0
https://www.reddit.com/r/aviation/comments/1nzet3a/flight_a_...
Quoted:
Incident: Malta Air B738 at Prestwick, Edinburgh and Manchester on Oct 3rd 2025, landed below minimum fuel By Simon Hradecky, created Sunday, Oct 5th 2025 14:39Z, last updated Friday, Oct 10th 2025 15:02Z
A Malta Air Boeing 737-800 on behalf of Ryanair, registration 9H-QBD performing flight FR-3418 from Pisa (Italy) to Prestwick,SC (UK), was on final approach to Prestwick's runway 20 when the crew went around due to weather. The aircraft entered a hold, then attempted a second approach to runway 20 about 30 minutes after the go around, but again needed to go around. The aircraft again entered a hold, about 10 minutes after entering the hold the crew decided to divert to Edinburgh,SC (UK) where the aircraft joined the final approach to runway 24 about one hour after the first go around but again went around. The aircraft subsequently diverted to Manchester,EN (UK) where the aircraft landed on runway 23R about 110 minutes after the first go around.
On Oct 5th 2025 The Aviation Herald received information that the aircraft landed below minimum fuel with just 220kg fuel (total, 100kg in left and 120 kg in right tank) remaining.
The aircraft returned to service about 13 hours after landing.
On Oct 10th 2025 the AAIB reported the occurrence was rated a serious incident and is being investigated.
A passenger reported after the first go around at Prestwick the crew announced, they would do another attempt to land at Prestwick, then divert to Manchester. Following the second go around the crew however announced they were now diverting to Edinburgh, only after the failed approach to Edinburgh the crew diverted to Manchester.
Nothing beats a Jet2 holiday...
Ryanair: Cutting cost at all cost
Each passenger will be required to bring a 5 gallon can of JET A.
The headline is about the landing, but the issue here happened at takeoff. There were 100 mph winds at the destination and this was their 4th fallback attempt and their third airport. This flight should never have taken off, the risk of multiple diversions was easily predictable, but the flight took off headed toward an airport in dangerous conditions, got diverted to a second airport that was just as dangerous, then finally to a third where conditions were so bad other flights were being cancelled (https://uk.news.yahoo.com/storm-amy-brings-flight-chaos-2019...) and where it finally landed because it was either land at that airport or land somewhere that is not at all an airport. Once this flight was in the air, disaster was more or less inevitable and we lucked into a narrow eviting window.
This very recent Mentour documentary is extremely relevant, came to mind immediately. Multiple redirects due to bad weather, extreme "Get-there-itis" and eventually running out of fuel.
Great edutainment if you're feeling in the mood for that. If you're inpatient you can skip to 14 minutes, before that it's just backstory.
https://www.youtube.com/watch?v=vK_7q9tixX4
On the positive side, if they had made a crash landing with so little fuel, there would not likely have been a fiery explosion, and many more passengers would have survived than normal?
Air + fuel explodes just fine. You really don't want to crash an airliner. At landing speed the number of people dead will still be > 0 and the remainder has a good chance of being injured seriously.
For instance:
https://en.wikipedia.org/wiki/Turkish_Airlines_Flight_1951
This happened at landing speed (the airport is only a few hundred meters from the crash site) and the plane was at the end of its flight from Turkey, it did not catch fire. Still, 9 people perished and the remainder were all but one injured 11 of them seriously.
that was equipment failure crew had to fight it, not something predictable like running out of fuel
Only 7% died, pretty good for a plane of that size with a rough landing.
Dunno about "only" ... 99.99998% of flights kill 0% of their passengers. Even if "just" one passenger dies in an incident, your flight is already in the 0.00002th percentile for safety, very bad!
Yes, even though that is a harsh conclusion to make and for the families involved of course it doesn't matter at all. But as these come this was bad but still not nearly as bad as it could have been. They were about to cross one of the busiest highways in NL, another 100 meters and it would have been an entirely different story. The field they landed in is in the Haarlemmermeerpolder, so clay and it had just been plowed.
> and many more passengers would have survived than normal?
This[1] kind of crash landing is very rare (in that case there was no fire despite being immediately after take off, perhaps because of the cold). Normally an outcome like this is only reasonable to expect if you actually reach a runway despite being out of fuel. Like Gimli[2].
[1] https://en.wikipedia.org/wiki/Scandinavian_Airlines_System_F...
[2] https://en.wikipedia.org/wiki/Gimli_Glider
Well there'd probably be a fire but not a sustained fire which would improve survivability.
So this is about the stopping problem, but for airplane fuel, kinda?
Is it like in the car where you have no fuel left but there’s a reserve of another 10 liters?
It's more like
* enough reserve to waste some in traffic. On top of that * enough reserve to find gas station. On top of that * enough reserve to drive to neighbouring city for gas station. On top of that * enough to cruise 30 minutes around that neighbouring city looking for other gas station in case the previous ones were closed. On top of that * enough station to run around parking lot looking for space to park
Yes and no. I had this happen recently and looked into it.
My wife has been using my car, which is a Diesel Golf with a fuel capacity of 14.5 gallons. We set off driving one Saturday to visit my parents, and I noticed the fuel gauge was below empty already. By the time I got to the gas station, I put 14.3 gallons of fuel into it. I calculated that that works out to be about a cup and a half of fuel.
So once you hit empty on my car, you definitely have a ways you can drive still. I feel comfortable driving about 30+ miles, and it's never died on me. That puts it at no more than 1 gallon of fuel left in the car based on my experience (not scientific I know, but I've owned 2 of these cars, with about 190k total driven miles). It's a lot less than 10 liters from E to Dead on the roadside.
You shouldn't tempt fate with a diesel, or any direction injection car for that matter. The high pressure pump will shred itself very quickly as the diesel is used for lubrication.
probably depends between cars. on my old civic fuel light is ~5L/1.3 gallons
The plane landed with approx 67 gallons of fuel. They typically land with 670 gallons.
A US gallon of Kerosene weights approx 6.5 lbs
> The pilots had been taking passengers from Pisa in Italy to Prestwick in Scotland on Friday evening, but wind speeds of up to 100mph meant they were unable to land.
> After three failed attempts to touch down, the pilots of Ryanair flight FR3418 issued a mayday emergency call and raced to Manchester, where the weather was calmer.
#1 - if Prestwick had wind speeds up to 100mph, then why the h*ll was the airport not closed down?
#2 - if the pilots had experienced conditions that dire during their first two landing attempts at Prestwick, then why the h*ll did they stick around for a third attempt?
EDIT: The article's a big vague, but it seems to have been 2 attempts at Prestwick, then 1 at Edinburgh, then the last-minute "oops, do I really want to die today?" decision to run to Manchester.
Looks like the third attempt was actually in Edinburgh
The third attempt was in Edinburgh, looks like.
The third attempted landing was in their diversion airport, Edinburgh, not a third at Prestwick.
The Guardian can’t be trusted with their sensationalist headlines.
The flight couldn’t land in 3 other airports and eventually declared emergency.
Another metric conversion error?
Sounds like pilot error - they didn't pay the extra fee to have reserve fuel.
"Worth it" - Ryanair probably
I imagine the next step will be RyanAir asking passengers to carry fuel cans onto the plane. B*tards.
Between overworked, understaffed ATC and undertrained pilots, I'm expecting some major disasters in the coming years.
One of the problems with modern internet discourse is there is an implicit assumption that the problem of one country is automatically the problem of another country.
I think that's just Americans tbh.
Flights operate internationally?
Yes, between other countries without having to go via the US!
Internationally yes, but Ryanair don't travel transatlantic.
> Between overworked, understaffed ATC and undertrained pilots, I'm expecting some major disasters in the coming years.
Maybe in the US, but this story is based in Europe, each country maintains a regulated standard and there are no EU wide disruptions that have ever happened to the best of my knowledge. Also Ryanair don't travel transatlantic flights.
Three weeks ago in Nice, France it was a fraction of a second away from two A320s crashing [0] and possibly hundreds of deaths, similar to Tenerife disaster [1].
Investigation is ongoing and many factors are at play (bad weather, extra work for ATC due to that, confusing lighting of runways etc) but also, from French media reports, there used to be 15 people per shift 5y ago in Nice ATC, now there are just 12, and traffic is higher.
Many people left the profession during Covid and haven't been replaced.
[0] https://avherald.com/h?article=52d656fd&opt=0
[1] https://en.wikipedia.org/wiki/Tenerife_airport_disaster
Mistakes and disasters happen, unfortunately the safety we have while flying today has been written in blood, but there is no major understaffed ATC and undertrained pilots in general as mentioned.
15 down to 12 in 5 years with more traffic is not out of the question with advancements in technology but of course, if there is a report that shows understaffing then absolutely it should be addressed straight away and it will be, by the French government.
Ryanair does use low-hour fresh-out-of-training pilots though. Certainly not the only airline that does that either.
Why? Is ATC a problem in other countries than the US? Are they also under training pilots? If anything RyanAir with its flamboyant history of cost cutting (CEO always threatening to charge for use of the onboard lavatory) seems a more likely source than the flying infrastructure itself.
Ryanair has a very good safety history, among the highest in the world.
They make outrageous claims for publicity, and their customer experience is all about hidden extras and "gotcha" pricing, but I don't think they fuck around when it comes to safety.
They know that with their reputation they would be sunk if they did have a major incident.
It's both true that Ryanair has very good safety record, and that in the past there were incidents with them landing on low fuel.
https://www.eurocockpit.eu/news/mayday-mayday-wins-over-ryan...
> In 2012 and 2013 “Brandpunt Reporter” broadcasted a two episode TV investigation in which Ryanair pilots, speaking anonymously, raised concerns about the airline’s fuel policies and company culture. The pilots revealed that the company may be exerting pressure on them to minimize the amount of fuel they take on board – a practice which limits significantly the fuel costs for the company but could jeopardise safety in certain circumstances. The direct reasons for this broadcast were 3 emergency landings of Ryanair aircraft in Valencia Spain on the 26 July 2012, within a short timeframe due to low fuel levels.
So it's sunk? They just had a major incident.
Let's wait for the investigation results before coming to that conclusion.
What indication is there that our pilots are undertrained?
I am just a PPL, and that was not an easy thing to accomplish (most pilots complete 50% more hours than required before they are able to pass that test), but my impression is that western training standards for commercial pilots are incredibly high, and the safety record seems to back that up.
Its arguably too high, constraining the supply of pilots, and the supply of well-paying jobs, resulting in things like Colgan Air Flight 3407.
In the US, I think that's probably true especially using hours as a proxy for training.
The EU has shown us that you can safely have far fewer hours.
As a pilot I do think that nothing replaces butt in seat, but I also think that 1500 hours of instructing/aerial surveying/hour building is well into the diminished marginal returns area.
Internet vibes, basically.
This had nothing to do with any of that tho.
Pilots are ultimately the ones who are responsible for when and where to land, when to divert, and how much fuel to take along.
In this case, they likely had adequate fuel for, the usual eventualities but the weather in Scotland was particularly bad that night across the whole country (source: I live near Prestwick airport).
Either Edinburgh (on the east coast) or Prestwick (on the west coast) are ok (one or the other or both) but in this case neither was suitable so the nearest was Manchester - definitely an edge-case.
I don't know how much fuel they had, or if they could've fitted any more on the plane but it was unusual circumstances.
There was a military plane right behind it with the same issue that night too.
Were these pilots undertrained?
I've never heard of any of these problems with RyanAir. They treat you as less than cattle and generally their service is shit, but I'm not aware of RyanAir being unsafe.
Actually, in a quick check it seems the total fatality count for RyanAir is zero, with only two (on-fatal) major incidents (2008, 2021). That's seems a pretty good track record considering the amount of flights they do.
Yeah there's a lot of hatred of Ryanair given their somewhat pugnacious attitude. But as far as I know they don't mess around when it comes to safety.
Closely followed by the ritual lampooning of some senior middle managers who by the fish-in-barrel method were discovered to not be doing very much.
Story time, from my past.
Waiting on full flight in Europe, good airport, for take off. Pilot says over speaker : " We are delayed becuase FUEL guy got UPSET on tarmac and has QUIT. We know need someone ELSE to fill the plane with FUEL. " Said in a COMPLETELY nonchalant voice.
Immediately I get concerned, try not to think what cause a FUEL TECH to QUIT regarding THIS PLANE and fuel issue. Just close my eyes, relax.
2 minutes later pilot comes on intercom again "For some WEIRD reason, someone wants to get off the plane. Now we have to wait for ground crew to find his suitcasebecause of rules. How annoying.."
Plane waits for an hour on tarmac for BOTH passenger to get off and for FUEL to be finally "resolved".
Arrive eventually at destination.
Most of the trouble would have been avoided if the pilot had not sounded nonchalant about a "NON ISSUE about FUEL that a technician just QUIT OVER". I swear i even rememebr saying the statement with a hint of humour, like what on earth is the problem.
This is a true story, and the fact this incompetence happened to me, well I wouldnt have believed it otherwise.
lacking fuel in plane that has not started flying isn't exactly something that should stress anyone and most definitely non issue