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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

#391

Post by PunchyHamster »

jacquesm wrote: post #49
deadbabe wrote: post #38

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 Turke…

that was equipment failure crew had to fight it, not something predictable like running out of fuel

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

#392

Post by PunchyHamster »

RajT88 wrote: post #348
moltar wrote: post #287

Is it like in the car where you have no fuel left but there’s a reserve of another 10 liters?

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 e…

probably depends between cars. on my old civic fuel light is ~5L/1.3 gallons

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

#393

Post by goodcanadian »

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?

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.

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

#394

Post by PunchyHamster »

moltar wrote: post #287

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

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

#395

Post by aunty_helen »

RajT88 wrote: post #348
moltar wrote: post #287

Is it like in the car where you have no fuel left but there’s a reserve of another 10 liters?

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 e…

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.

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

#396

Post by PunchyHamster »

ionwake wrote: post #355

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…

lacking fuel in plane that has not started flying isn't exactly something that should stress anyone and most definitely non issue

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

#397

Post by mulmen »

hshdhdhehd wrote: post #378
mulmen wrote: post #354

Earlier quoted context omitted.

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 p…

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.

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

#398

Post by XorNot »

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.

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

#399

Post by krisoft »

recursive wrote: post #333
krisoft wrote: post #282

Earlier quoted context omitted.

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.

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.

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

#400

Post by anonymars »

howard941 wrote: post #347
anonymars wrote: post #294

Earlier quoted context omitted.

> 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

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"
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