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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

#91

Post by wasmitnetzen »

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:/…

There's a YouTube video[1] of the German Armed Forces showing an emergency airfield on a German Autobahn from 1988. It's subtitled, but only in German. Autotranslation is available though.

[1]: https://www.youtube.com/watch?v=F_cxkF6qSY8

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

#92

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…

There was a shortcut: "But if they had looked at the text of the SB, they would have realized that they missed a step: they were also supposed to replace the hydraulic tube which attached to the pump." With the old tube, the clearance was insufficient to avoid contact while in use.

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

#93

Post by iso1631 »

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'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 will move during flight.

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

#94

Post by kayodelycaon »

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…

There isn’t a need for a flight engineer. The non-flying pilot (pilot monitoring)’s entire job is to be looking at the big picture.

If something goes wrong, they are the ones managing the checklist.

In any case, the automation handles the vast majority of flight engineer duties. And fuel leak warnings have been added now.

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

#95

Post by isolli »

bambax wrote: post #55
chx wrote: post #50

Earlier quoted context omitted.

Another very famous incident is the Gimli Glider which was also a result -- as almost all of these are -- of quite a string of issues, including, astonishingly, the mixup of imperial and metric units. The report on the accident found fault with Air Canada procedures, training, and manuals. Everything else was, I guess, peachy :P

The Gimli Glider is covered by Admiral Cloudberg here: https://admiralcloudberg.medium.com/a-mathematical-miracle-t... This story is more ambiguous. The plane should never have left the ground and the captain committed a serious error when he decided to depart with no fuel gauge working. According to airline procedures at the time, no plane could be dispatched without working fuel gauges. That wasn't up for debate, i…

In both cases, I would pass a similar subjective judgment. Both pilots made a series of mistakes, but such mistakes are made every day, most often without consequence. However, both ultimately saved their plane when it mattered, thanks to exceptional flying skills. I have nothing but respect for them.

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

#96

Post by peteradio »

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.

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

#97

Post by kqr »

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…

> The infrastructural insurance spent to prevent lives lost in air travel appears to be much higher than lives on road travel. Could it be that the insurance is for the aircraft, not the lives?

I would be surprised if the cost of equipment and training pilots and whatelse was not factored in.

But the major driver might be that you have to pay for more expensive insurance to get regular people to strap themselves into something going many miles per hour many feet above the ground. Not because it's inherently less safe (though I would argue it is) but because the prospect is scarier!

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

#98

Post by bambax »

iso1631 wrote: post #93
bambax wrote: post #82

Earlier quoted context omitted.

> 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'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…

0.635 mm is indeed an odd number. The thickness of a piece of 80gsm paper is 0.065 mm, so maybe what is meant is "about the thickness of ten sheets of paper"...?

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

#99

Post by plasticchris »

iso1631 wrote: post #93
bambax wrote: post #82

Earlier quoted context omitted.

> 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'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.

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

#100

Post by bambax »

isolli wrote: post #95
bambax wrote: post #55

Earlier quoted context omitted.

The Gimli Glider is covered by Admiral Cloudberg here: https://admiralcloudberg.medium.com/a-mathematical-miracle-t... This story is more ambiguous. The plane should never have left the ground and the captain committed a serious error when he decided to depart with no fuel gauge working. According to airline procedures at the time, no plane could be dispatched without working fuel gauges. That wasn't up for debate, i…

In both cases, I would pass a similar subjective judgment. Both pilots made a series of mistakes, but such mistakes are made every day, most often without consequence. However, both ultimately saved their plane when it mattered, thanks to exceptional flying skills. I have nothing but respect for them.

Okay, and agreed, but in the case of the Gimli Glider the captain disregarded procedures. That's not just an error, it's a fault (he was suspended for a while because of that, and rightly IMHO).
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