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Ryanair flight landed at Manchester airport with six minutes of fuel left

theguardian.com

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Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#251

Post by TheJoeMan »

abtinf wrote: post #40
jacquesm wrote: post #23

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 interes…

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?

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.

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#252

Post by throwup238 »

hermannj314 wrote: post #239
MadnessASAP wrote: post #188

Earlier quoted context omitted.

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.

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#253

Post by scrumper »

whycome wrote: post #217
scrumper wrote: post #163

Earlier quoted context omitted.

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. ED…

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…

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!

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#254

Post by csours »

dTal wrote: post #85
jacquesm wrote: post #75

Earlier quoted context omitted.

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.

You get that energy back on descent, no?

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.

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#255

Post by [deleted] »

Hackbraten wrote: post #183
scrumper wrote: post #163

Earlier quoted context omitted.

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. ED…

> 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.

[deleted]

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#256

Post by inoffensivename »

w10-1 wrote: post #99

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?

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.

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#257

Post by throwup238 »

yodelshady wrote: post #155
jacquesm wrote: post #56

Earlier quoted context omitted.

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.

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)

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#258

Post by hencq »

nostrademons wrote: post #158
fidotron wrote: post #87

Earlier quoted context omitted.

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…

> 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?

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#259

Post by MaxikCZ »

jacquesm wrote: post #181
MaxikCZ wrote: post #174

Earlier quoted context omitted.

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. (O…

(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…

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.

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