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Crisis over The Atlantic: The near crash of Air Transat flight 236

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Re: Crisis over The Atlantic: The near crash of Air Transat flight 236

#111

Post by t0mas88 »

relix wrote: post #24
marze wrote: post #21

I think if you asked the engineers who designed the airbus in question, could you create a "leak" warning, using just the existing sensor suite, they'd say "sure". You know the fuel level in each tank, and have a good estimate or actual flow data on engine fuel usage. Simple math says "leak" or "no leak". If that would work, it is surprising it isn't in the software.

Make it broader - before take-off, pilots enter the expected destination (or expected distance). During cruising, computers keep track of how much fuel is being used (lost) per unit of time, and projects forward to see if they can still make their expected destination or not. If the number does not reach within expected margins, then show an error. This protects against leaks, but also miscalculation of fuel needed b…

This already exists and in a much more advanced way. The flight management system calculates the expected fuel on landing based on the route, wind data, different fuel usage at altitudes etc.

It's not as simple as "fuel per time" because fuel usage and speed change massively with altitude.

What was missing here was a big warning to the pilots (that has since been added). But it's also standard procedure at all airlines to monitor fuel and required fuel calculations, which could have helped this crew if they did it earlier.

Re: Crisis over The Atlantic: The near crash of Air Transat flight 236

#112

Post by kayodelycaon »

Gasp0de wrote: post #90
avidphantasm wrote: post #88

I think it’s unreasonable to pin the mistake on the pilots for not running all the checklists. This is where a flight engineer would come into play in my lay opinion. The pilots were tactically focused; they were trying to keep the plane in the air. You need someone on the flight deck who is looking at the bigger picture, doing the fuel calculations (even if the automated systems aren’t warning about certain fuel-rel…

They did contact the engineering department. Maybe it would have sufficed to have a telemetry uplink back to the engineering department. Should be doable with Starlink etc. soon enough.

Aircraft already have telemetry uplinks via satellite. See ACARS. https://en.wikipedia.org/wiki/ACARS

Re: Crisis over The Atlantic: The near crash of Air Transat flight 236

#113

Post by nick889996544 »

plasticchris wrote: post #99
iso1631 wrote: post #93

Earlier quoted context omitted.

I'm amazed they can measure the distance between two real non-fixed components down to a few micrometers (they wrote 0.635mm, implying somewhere between 630um and 640um) If 0.635mm (an odd number itself which happens to be exactly 1/40th of an inch, or "25 thous" in American sizes) and they let it go that sounds really odd. That's literally the size of a grain of sand. If the concern is rubbing, sure that implies it…

It sounds to me like they stuck a machinists shim in there, effectively a bit of precisely measured metal.

Shim feeler gauges would be readily available in most shops checking wear on moving parts. 0.0025 inches (0.635mm) was included in the first high quality (gearwrench brand) set that I looked up online.

Re: Crisis over The Atlantic: The near crash of Air Transat flight 236

#114

Post by mannykannot »

bambax wrote: post #82
dsfyu404ed wrote: post #77

Earlier quoted context omitted.

What shortcuts? Spec said no touchy between tubes. Tubes no touchy when aircraft left the hanger? Seems good to me. These are the kinds of failures you get when you try to proceduralize everything with foolproof procedures, checklists, run-books, processes, etc. The maintenance people didn't even know they were making a judgement call. Had the technicians sleeved the offending tubes with appropriate chafing gear and…

> But maintenance people in aviation aren't really ever exercising those creative problem solving skills This is the opposite of what happened. The engineers were confronted with a novel and unexpected problem, and instead of following procedure (which they lacked access to) they applied "creative problem solving skills". From TFA: > Although it was possible to install the post-SB fuel lines and hydraulic pump with a…

I wonder if this nut, if not every nut on an ETOPS airliner (or in general), has a specific torque value. If adjusting the torque can open up a gap, presumably doing so could close one as well.

Re: Crisis over The Atlantic: The near crash of Air Transat flight 236

#115

Post by rejectfinite »

noduerme wrote: post #34
robga wrote: post #9

Interesting that they call Lajes a “military airfield”. On the Azorean island of Terceira, Lajes (TER) is a mixed use airfield that is the commercial landing strip of the island since the 1930s, as well as having a multi-national military base on the other side since the 1940s. There is a picture in the story. The NTSB report called it a military airbase, and other reports say “Military air traffic controllers guided…

One of the coolest emergency airfields I can think of is, literally, Uruguay Route 9, along the coast of the country, where a 2-lane highway becomes an enormous runway that you continue driving along. I don't know if there were any famous landings there; I heard it's only used rarely by the Presidential jet. Here's where it is: https://goo.gl/maps/fpwxuPzGVDtDEKmB8 and what it looks like when you drive on it: https:/…

A lot of roads are runways for JAS Gripen in Sweden/EU :)

https://www.youtube.com/watch?v=2-2Xde54xz4

Re: Crisis over The Atlantic: The near crash of Air Transat flight 236

#116

Post by q1w2 »

peteradio wrote: post #96
kqr wrote: post #47

The actual report: http://www.fss.aero/accident-reports/dvdfiles/PT/2001-08-24-... One of my pet peeves: the first 7 "causes and contributing factors" effectively blames the engine technicians for taking shortcuts. Nowhere does it say anything about the scheduling pressure from management that made the technicians consider shortcuts in the first place. If you have hiring and firing power and you tell someone they nee…

Replace the use of the word "risk" with "gamble" and then it would paint the scene correctly.

Semantics don't solve problems.

Re: Crisis over The Atlantic: The near crash of Air Transat flight 236

#117

Post by mannykannot »

dsfyu404ed wrote: post #77
kqr wrote: post #47

The actual report: http://www.fss.aero/accident-reports/dvdfiles/PT/2001-08-24-... One of my pet peeves: the first 7 "causes and contributing factors" effectively blames the engine technicians for taking shortcuts. Nowhere does it say anything about the scheduling pressure from management that made the technicians consider shortcuts in the first place. If you have hiring and firing power and you tell someone they nee…

What shortcuts? Spec said no touchy between tubes. Tubes no touchy when aircraft left the hanger? Seems good to me. These are the kinds of failures you get when you try to proceduralize everything with foolproof procedures, checklists, run-books, processes, etc. The maintenance people didn't even know they were making a judgement call. Had the technicians sleeved the offending tubes with appropriate chafing gear and…

> These are the kinds of failures you get when you try to proceduralize everything with foolproof procedures, checklists, run-books, processes, etc.

Aviation safety is utterly dependent on procedures, checklists, run-books and processes. The fact that things sometimes fall through the cracks is no argument against them.

Re: Crisis over The Atlantic: The near crash of Air Transat flight 236

#118

Post by mannykannot »

avidphantasm wrote: post #88

I think it’s unreasonable to pin the mistake on the pilots for not running all the checklists. This is where a flight engineer would come into play in my lay opinion. The pilots were tactically focused; they were trying to keep the plane in the air. You need someone on the flight deck who is looking at the bigger picture, doing the fuel calculations (even if the automated systems aren’t warning about certain fuel-rel…

It is an objective fact that if they had run the checklists they would have arrived with fuel remaining, and also that they had plenty of time to do so. If we can't say this, how can we learn anything from the investigation?

Re: Crisis over The Atlantic: The near crash of Air Transat flight 236

#119

Post by dkarl »

mannykannot wrote: post #103
kqr wrote: post #47

The actual report: http://www.fss.aero/accident-reports/dvdfiles/PT/2001-08-24-... One of my pet peeves: the first 7 "causes and contributing factors" effectively blames the engine technicians for taking shortcuts. Nowhere does it say anything about the scheduling pressure from management that made the technicians consider shortcuts in the first place. If you have hiring and firing power and you tell someone they nee…

In this case, there is no evidence here of any ontoward pressure on the maintenance crew, and there is not even any evidence that anyone in the chain of command outside of those involved in the task had any inkling that this might develop into a schedule disruption. On the contrary, the evidence strongly suggests that the maintenance crew did not feel they were under any special pressure: in their minds, they had fou…

This reminds me of times in the first couple of years of my career, where me and some other junior people were terrified that we weren't going to get a project done on time. We would be wracking our brains for out-of-the-box ways to get it done, whispering to each other, having trouble sleeping, and then we would be amazed that the lead developer would simply go to our manager (while we were still desperately brainstorming) and tell him we wouldn't finish on time. And nothing awful would happen. The lead developer was fine. We were fine. The project finished late. Nobody got fired.

Now as a senior developer it's hard for me see why I was so terrified. Some managers yell and bluster. (Or, they used to, back in the day.) Some managers shame and insinuate. Some managers obliquely threaten. But they all, no matter how they express their authority, have to face up to the unpredictability of project planning. The question is not whether your manager is nice or mean. The question is, do they really think they're better off firing you and replacing you? Whether because they think they can get an upgrade or simply to pin the blame on you for something. After you've been around the block once or twice, you understand that a manager who is chill to your face is ultimately subject to the same motivations as a manager who uses stress as a weapon.

I wonder what it's like for airline mechanics? They are represented by unions. I would think that safety infractions would be the real potential career killers, but that's just me guessing.

Re: Crisis over The Atlantic: The near crash of Air Transat flight 236

#120

Post by IIsi50MHz »

Reason077 wrote: post #12
ricardobayes wrote: post #8

Earlier quoted context omitted.

Seems a bit weird to say "never watch youtube". It's like never reading a book anymore because someone gave you a bad one. It's up to you to filter out content you dislike, just like with everything else.

> ”It's up to you to filter out content you dislike” YouTube’s algorithm is pretty good at doing this for you!

Er, at doing the inverse, for me.

"Oh, you're watching a video on foo? Here's a list of video clickbait trash, with sometimes one more video on foo thrown in.

"Oh, you either never open or always bail out of 'shorts'? Here are more of them!"

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