Ryanair flight landed at Manchester airport with six minutes of fuel left • Hacker News Board

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

#411

Post by dclowd9901 » Sat, Oct 11, 2025, 2:37 AM UTC

AceyMan wrote: post #68

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…

> you can never plan on using it

In off-roading, we have a similar rule with 4 wheel drive. You don't use it to go in, you use it to get out.

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

#412

Post by dredmorbius » Sat, Oct 11, 2025, 2:44 AM UTC

Schiendelman wrote: post #372

dredmorbius wrote: post #303

Earlier quoted context omitted.

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

Sing louder, damnit!!!

;-)

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

#413

Post by TZubiri » Sat, Oct 11, 2025, 2:45 AM UTC

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…

>I'd be very wary to get ahead of the investigation and make speculative statements on how this could have happened

>Ryanair

I wouldn't be so wary.

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

#414

Post by TZubiri » Sat, Oct 11, 2025, 2:47 AM UTC

mr_00ff00 wrote: post #409

heelix wrote: post #403

Earlier quoted context omitted.

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 requi…

Why does it burn fuel so fast?

My guess is higher air density means more wind resistance, which acts as negative forward acceleration.

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

#415

Post by TZubiri » Sat, Oct 11, 2025, 2:50 AM UTC

loverofhumanz wrote: post #79

abtinf wrote: post #40

Earlier quoted context omitted.

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’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.

I think the argument is that this is precisely the tail end of exceptional conditions overfueling is designed for. If it's typical to fill fuel for 4 hours on a 2 hour flight, and the flight took 4 hours. It seems like this is exactly why they overfuel to 4 hours. If this happens once every 100k flights, then it doesn't even beg the question of "why aren't we overfuelling to 4.5 hours".

This is just clarifying the question from the perspective of an outsider.

That said, an investigation would be pretty reasonable, even if only to confirm that the abornamlity were forces majeures

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

#416

Post by hshdhdhehd » Sat, Oct 11, 2025, 3:00 AM UTC

mulmen wrote: post #397

hshdhdhehd wrote: post #378

Earlier quoted context omitted.

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.

Assumes everyone is in medium to high density urban areas.

I like the idea, rural life excepted, but hard to imagine sprawl will ever be replaced.

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

#417

Post by darthwalsh » Sat, Oct 11, 2025, 3:26 AM UTC

XorNot wrote: post #398

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…

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.

Isn't midair refueling notoriously difficult to get right? The headlines would become "airliner crashes after crew couldn't thread the needle for 45 min"

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

#418

Post by jacquesm » Sat, Oct 11, 2025, 3:30 AM UTC

dotancohen wrote: post #364

jacquesm wrote: post #181

Earlier quoted context omitted.

(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…

> 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.

So it seems. But because you want to land you then want to shed all that velocity. So you 'get it back' only to have to waste the bigger fraction of it. A go around is much like a mini take-off, you just miss the runway portion of it.

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

#419

Post by jacquesm » Sat, Oct 11, 2025, 3:34 AM UTC

TZubiri wrote: post #415

loverofhumanz wrote: post #79

Earlier quoted context omitted.

"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.

I think the argument is that this is precisely the tail end of exceptional conditions overfueling is designed for. If it's typical to fill fuel for 4 hours on a 2 hour flight, and the flight took 4 hours. It seems like this is exactly why they overfuel to 4 hours. If this happens once every 100k flights, then it doesn't even beg the question of "why aren't we overfuelling to 4.5 hours". This is just clarifying the qu…

> If this happens once every 100k flights, then it doesn't even beg the question of "why aren't we overfuelling to 4.5 hours".

- This does not happen once every 100k flights. That's once per day

- If this were happening once every 100k flights we would be adding another half hour to the reserve tomorrow.

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

#420

Post by jacquesm » Sat, Oct 11, 2025, 3:37 AM UTC

bluGill wrote: post #380

jacquesm wrote: post #326

Earlier quoted context omitted.

Go arounds are not failures.

They are expected situations, but still a failure of the original plan.

They are not a failure of the original plan, they are a mandatory component of the original plan that if everything is nominal never gets executed. Every pilot on approach is ready for one or even more go-arounds and they happen quite frequently for a variety of reasons.

They happen a few hundred times per day at ~100 k flights.