Comment by jacquesm

> E.g. are there consequences for pilots who cause delays for passengers?

I'd imagine heavily depends on how often that happens vs other pilots on same route. Tho I'd imagine consequences are "here is more training".

As someone totally ignorant of British airports, a Google maps search for "airports northern england" shows Teesside, Carlisle, and Newcastle all significantly closer to Edinburgh than Manchester. Are these not places where a 737 under emergency could land? Or was the weather also bad there?

At the point they left it, they still had about an hour and 20 minutes of fuel remaining, with an alternate airport 20 minutes away. They had not declared an emergency, so they were in with any other traffic waiting for takeoff and landing. (Which does make me wonder, did any other planes try to land at Prestwick at the time and how did they fair?)

When you declare a fuel emergency or even urgency, there's often follow up to figure out why (mechanical issue? problem with dispatch? problem with flying technique? exceptional weather condition that could be forecast better? etc). And there is plenty of data in aviation to know what happened.

Dispatch knows how much fuel they say they put in.

Your flight time, speeds, and profile are known.

ACARS may be reporting fuel use throughout the flight.

etc, etc, etc.

Random spot checks. Every day at every airport some of these will get verified. Also, the next pilot would have to be willing to cover for you because they are going to have to falsify their records to make your trick invisible. You record the amount of fuel in the tank when you take command of the aircraft, the amount of fuel that was loaded and from that it is trivial to compute how much was left the last time it landed.

Lets say a plane crew claims low fuel.

The pilot in charge has to file a writeup.

When someone accepts the writeup, there's a random chance it's selected for followup. If/when they discover there was enough fuel, it will affect the career(s) of person(s) involved.

First, generally, people don't like having to do paperwork, and especially don't like doing paperwork to help you land a little quicker.

While one time may not be a fireable offense, you will find you career affected in the number of ways people can find to be uncooperative with you, or not support you when you attempt to advance your career within the company.

Developing a habit would lead your interlocutors to escalate the situation, which would lead to discipline up to and including the company firing person(s) involved.

also carrying less fuel does save on fuel usage

Which specific civil aviation incidents are covered by some secret classification?

It’s generous of the classifying authority to send to the ICAO meeting somebody both appropriately credentialed to know about the information in question, and willing to talk coyly about it. Did these additional incidents inform the policy discussions at the meetings you attended?

I am not saying you are wrong, but both Type I and Type II errors are problematic. What if the pilot is wrong?

Korean Air Flight 801 could have used someone 2nd guessing a pilot. They didn't until they were almost dead and then it was too late. Not 2nd guessing the pilot was a really really bad idea.

This incident is known as the Gimli Glider and was actually due to multiple failures before the pound-kilogram issue (and the backdrop of Canada's then-recent metrication) even became relevant: https://en.wikipedia.org/wiki/Gimli_Glider

Perhaps. If the pilot knows that the ATC can see he's full of it, he might be less likely to lie.

Those who still do can be grounded and be moved into management or take up a career in politics.

You mean that ATC would abuse their position by making planes circle as long as they have some fuel left?

As I wrote elsewhere in this thread I actually wrote software to estimate the amount of fuel a jet should load to comply with the rules. This was commissioned by the airline and they were scared shitless that they would ever be found to be in breach of the regulations on this aspect. It is one of those red lines that you really do not wish to cross. There are other aspects of flight where you are right but this particular one is different.

The main reason why airlines would like to take the least amount of fuel is because it immediately increases payload capacity and thus flight efficiency. This being a cut-throat market there is a serious incentive to cut it as fine as possible. So the regulations around this particular issue are incredibly strict: you have to have a certain amount of fuel left upon landing, you have to write up truthfully how much you still had left and you will be investigated without fail if you cut into the reserve. The good thing about unions here is that they help to make sure that pilots know they are safe reporting truthfully because the airlines can not retaliate if they would pressure the pilot to not report an incident (which all pilots would normally definitely do). So they're a factor, but it is the regulator that writes the rules here and they are super strict about this.

And that's immediately why the calculation of the estimate becomes so important: you now have 30 minutes (or 45, depending) of deadweight + the deadweight for two alternates and an x amount of time in a holding pattern, plus up to three go-arounds. That really adds up, so you have to do your best to get the calculation as close as possible to what it will be in practice without ever cutting into that reserve.

It took me the better part of a year and massive amount of learning to write a small amount of code + associated tests to pass certification. It also taught me more about software engineering (as opposed to development) than anything I did up to that point in time and it made me very wary about our normal software development practices.

I think the literal fear of death _might_ be motivation enough for pilots to advocate for safety? And if they want to fire you, would you want to work for them anyways?

The union is a nice backstop for issues around the edges that come up with corporate, but the real backstop is the pilots’ licensing. By making them directly responsible for the plane as PIC, it gives them leverage over their employer that few other professions have. AIR-21 gives them significant protection from retaliation and the ASRS is confidential. ALPA helps them navigate that mess if it comes to it, but that’s the real legal backing that pilots have.

Same thing happens with Professional Engineers regardless of whether they are employed or work as independent consultants/firms. They’re legally responsible for the bridges and other infrastructure they sign off on with laws protecting them from employers and clients.

(I fully support the ALPA and other unions, I just don’t think it plays as significant a role in following regulations as you claim)

If you land with less fuel than the legal minimum you are going to have a lot of explaining to do, there will be an investigation and you, the pilot and the airline will get enough headache from it that you will make bloody sure it does not happen again. The pilot(s) may not be able to fly until that investigation has run its course, the airline may get fined or warned if this is the first time it happened. In an extreme case the pilots may lose their license.

> It seems absolutely fair to say that, in this situation, the people - the pilots in particular, but also cabin crews, ATCs, engineers, and their unions, are the backstop worth observing and celebrating.

I will hold off on that conclusion until the report is in. There are so many possible root causes here that speculation is completely useless, and celebrations would be premature.

I think the thing that's being pointed out as overlooked when praising the employees and the unions, is the regulators, who are the people who play a very large part in making sure that the regulations are enforced. The regulations are just text in a database, but it's the regulators who actually make it happen. A pilot who wants to push back against a beancounter cutting corners has a union and a regulatory agency to back them up.

Is this a joke?

The test suite was much larger than the code. It took ages to get it certified, the calculations had to be correct to the last significant digit on reference problems to prove that the algorithms had been implemented correctly. This caused a bit of a headache because the floating point library that I used turned out to be slightly different than the one from the benchmark.

There are three different kinds of jet fuel and all are produced to strict standards, and then there are allowances for ppm water contamination (very low, to ensure the fuel system will never freeze at altitude or in freezing weather on the ground or at lower altitude).