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

#281

Post by Schiendelman » Fri, Oct 10, 2025, 7:05 PM UTC

phyzome wrote: post #247

rappatic wrote: post #136

> 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.

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.

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

#282

Post by krisoft » Fri, Oct 10, 2025, 7:09 PM UTC

recursive wrote: post #118

dTal wrote: post #85

Earlier quoted context omitted.

You get that energy back on descent, no?

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.

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

#283

Post by throwaway173738 » Fri, Oct 10, 2025, 7:09 PM UTC

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?

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.

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

#284

Post by behringer » Fri, Oct 10, 2025, 7:14 PM UTC

bluGill wrote: post #169

behringer wrote: post #88

Earlier quoted context omitted.

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.

Those landings are practiced from a reasonable altitude.

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

#285

Post by [deleted] » Fri, Oct 10, 2025, 7:14 PM UTC

db48x wrote: post #244

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…

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.

[deleted]

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

#286

Post by ecommerceguy » Fri, Oct 10, 2025, 7:16 PM 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'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.

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

#287

Post by moltar » Fri, Oct 10, 2025, 7:19 PM UTC

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

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

#288

Post by SoftTalker » Fri, Oct 10, 2025, 7:20 PM UTC

bilekas wrote: post #33

SoftTalker wrote: post #2

Between overworked, understaffed ATC and undertrained pilots, I'm expecting some major disasters in the coming years.

> 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.

Ryanair does use low-hour fresh-out-of-training pilots though. Certainly not the only airline that does that either.

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

#289

Post by sentientslug » Fri, Oct 10, 2025, 7:22 PM UTC

scrumper wrote: post #253

whycome wrote: post #217

Earlier quoted context omitted.

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 t…

With all due respect, you are the one that sidetracked the discussion, not the person that acknowledged AI

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

#290

Post by appreciatorBus » Fri, Oct 10, 2025, 7:23 PM UTC

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?

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"