If they have to touch and go, how long would it take until they get the plane around for another approach? In fact, you might not get as far as that touch and go and have to go around. You need some margin for all of these eventualities. The likelihood is low that these happen, but they have to be accounted for.
Sure, but the flight was a lot longer than planed. How much extra do we need. They declared an emergency, and thus put themselves at the front of the line. They had 6 more minutes to do that touch and go around if that happened, and since they were already in a low fuel emergency they get priority and so there is enough time to do that if they needed. (edit - as others have noted, 6 minutes with high error bars, so they could have only had 30 seconds left which is not enough)
They landed safely, that is what is important. There is great cost to have extra fuel on board, you need enough, but it doesn't look to me like more was needed. Unless an investigation determines that this emergency would happen often on that route - even then it seems like they should have been told to land in France or someplace long before they got to their intended destination to discover landing was impossible.
> They had 6 more minutes to do that touch and go around if that happened
6 minutes is way out of the comfort zone. They might not have made it in that case.
Correct, article says they landed with 220kg which is around 6 minutes of average fuel burn over an entire flight - bit less at cruise, a hell of a lot more at takeoff/climb.
So I don't think 220kg is enough to do a go-around in a 737 (well, a go-around would've been initiated with a bit more than 220kg in the tank - they burned some taxing to the gate - but you get my point.) I've read around 2,300kg for takeoff and climb on a normal flight in a 737-8. A go-around is going to use close to that, it's a full power takeoff but a much shorter climb phase up to whatever procedure is set for the airport and then what ATC tells you.
I just flew 172s but even with those little things we were told, your reserve is never to be used.
These people came very, very close to a disaster. Fortunately they had as much luck left as they did fuel.
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That’s about as useful as opening a fortune cookie and reading it off as an answer.
Straight from the horse’s mouth: https://web.archive.org/web/20230630013840/http://www.boeing...
In the first table they list 2307-2374 kg of fuel for takeoff and climb.
You’re talking to the wrong horse though.
Isn’t a 737-8 the max 8 variant? It uses newer dual CFM LEAP-1B engines. How does it compare? I can’t really find the data. The spec you’re referring to is for the older 737-800.
Another fortune cookie:
https://www.aircraft-commerce.com/wp-content/uploads/aircraf...
It suggests an overall savings of ~14% over the 737-800 but doesn’t look at specific takeoff/climb comparison.
I wasn’t posting the LLM output as a source of truth. I was just using it to question the uncited value. And I still really don’t know the answer. If you’ve got another data source I’d love to get it.
Why do people keep insisting on pasting LLM output to HN when every time it happens, it gets downvoted to oblivion? The community clearly doesn't want it. If we wanted to know a computer program's opinion about something, we could ask it ourselves.
I was using it to question that exact stated fuel consumption number without a citation. For hard data (like fuel consumption) getting a value from an LLM isn’t absurd.
If not absurd, it's very poor form. You should never use LLM as input for a discussion, nobody wants to hear that. Use it to search for authoritative sources.
It’s fine if you post an actual citation that you might have found through the LLM. Just posting AI slop is worse than useless, though, and also unpleasantly dystopian.
ok, how do we verify that?
Maybe he should ask Claude next.
That’s the point? I wasn’t suggesting it was correct. Just that the value is wildly different from their own non-cited number. The next stage was to get a citation from an actual datasheet. Their reasoning was nothing beyond “I’ve read”
I agree, well out of comfort zones. However to my reading multiple different things went wrong to get to this point.
That could be. We just don't know right now, but your intuition may well be correct, even if there is a single root cause there could very well be multiple contributory causes.
They failed to land at two airports before the third. I can't say if they made the right decisions but that already is two failures.
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.
How much extra do you need? Enough that a pilot/crew doing their job properly will never run out of fuel and crash.
So yes they will do an "investigation". It's not a criminal investigation. It's to understand the circumstances, the choices, the procedures, and the execution that ended with a plane dangerously close to running out of fuel.
This will determine if there were mistakes made, or the reserve formula needs to be adjusted, or both.
Don't tell me about cost, just stop. Let MAGA-Air accept some plane deaths to have cheap fares.
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.
I don't think that's all that true for airliners. Pilots definitely practice for engine-out scenarios during all levels of training up to the airlines, but the ability of a plane the size of a 737 to safely land on anything but a runway is...limited. And if you're low, slow, and trying to go around, that's not a lot of time to glide to ground that is "level enough".
i didn't mean to imply no runway landings. Landing on grass is questionable. They would practice water landings though
Those landings are practiced from a reasonable altitude.
Surely the issue is more that they decided to make so many attempts to land local. There should be a max level of attempts.
There is a lot of pressure on pilots to land local. But 3 go-arounds happens, not often, but it does.
Perhaps that decision needs to be removed from the airline and there needs to be an independent decision maker there.
Pilots are ultimately responsible for the aircraft, that's pretty much set in stone but if ATC would tell them to divert they would unless there already was an emergency.
There is a max level, and it is three.