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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

#361

Post by [deleted] »

philipallstar wrote: post #346
rz2k wrote: post #304

Earlier quoted context omitted.

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…

I'm sure we can all remember at least one person in any situation who will say something we find memorably awful.

[deleted]

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

#362

Post by cpncrunch »

nostrademons wrote: post #128
cpncrunch wrote: post #102

Earlier quoted context omitted.

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 out…

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.

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

#363

Post by jasonwatkinspdx »

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’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.

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

#364

Post by dotancohen »

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…

  > 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.

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

#365

Post by throw_a_grenade »

alwa wrote: post #209
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…

(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://aero…

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).

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

#366

Post by t0mas88 »

ecommerceguy wrote: post #286
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'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.

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

#367

Post by hshdhdhehd »

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.

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

#368

Post by jwsteigerwalt »

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.

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

#369

Post by hshdhdhehd »

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 dont know but maybe they should have diverted sooner. Maybe an hour into the flight?

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

#370

Post by hayleox »

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?

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.

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