James768
Topic Author
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Joined: Thu Dec 21, 2000 11:26 am

Swissair/Air France Crashes - Why...

Mon Mar 19, 2001 5:40 pm

Can someone tell me why Swissair 111 and the Air France Concorde crased - if we know yet.

I think know in the Swissair case faulty wiring caused the cockpit to fill with smoke - but why did it actually crash - loss of control (ie wires and controld burnt through ) - or crew disorientation?

And Air France Concorde - i mean i know a piece a metal got flipped up into the engine - causing a fire - but WHY did it crash - I mean with one engine out (allbeit on fire) - surely it should still have flown - or were two engines disabled (in which case was the cause of the crash effectively double engine failure) - or was it because it couldnt get its wheels up (ie stall)
 
Ikarus
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Joined: Mon Jan 08, 2001 10:18 pm

RE: Swissair/Air France Crashes - Why...

Mon Mar 19, 2001 5:48 pm

The crew followed standard emergency procedures (dumping fuel etc.) - but in this case it was a mistake. It cost them valuable seconds during which the cockpit filled up with so much smoke that they could no longer see any instruments, let alone outside. So the blind pilots crashed directly into the sea....

Concorde: 2 engines out, complete loss of control (the bit of metal probably hit the hydraulic system as well as punching the hole in the wing that caused the fuel leak that caused the fire...)

That's all I've heard - feel free to correct me, anyone!


Regards

ikarus
 
cedarjet
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RE: Swissair/Air France Crashes - Why...

Mon Mar 19, 2001 6:20 pm

SR111 - there are two theories. One is that the fire in the cockpit became so serious that the pilots abandoned the cockpit. Rumours from the investigation have intimated that the dead pilots were found down the back and melted metal was found on the captain's seat. The other theory suggests the crew became disorientated and bungled a recovery from a steep roll, a la JKF jr (if you suddenly find yourself in a steep descending turn, the first instinctive reaction is to pull up, but this will steepen the turn and usually result in s spin - you have to roll out THEN pull up).

AF4590 - the flight never got above V2, which is the minimum control speed with engine(s) out. As pointed out above, they basically stalled although how far they could have flown even with an extra 20 knots is debatable. The severity of the fire was certainly destroying control surfaces, hydraulic and electrical lines, structural integrety etc. They were aiming for Le Bourget but whether they would have made if the speed had been higher is questionable.

Personally, these two crashes were the worst two moments in modern aviation for me. The Concorde was a horrible, graphic disaster with enough time for the occupants to understand that they were about to die, but that was nothing compared to the ordeal of SR111 with the long preparations for ditching and the aircraft filling with smoke.
fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz
 
gerardo
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RE: Swissair/Air France Crashes - Why...

Mon Mar 19, 2001 11:10 pm

There has to be put a big question mark behind the statement, that SR111 could have landed savely, if they didn't follow the checklist. The aircraft still was above max. landing weight and was full of fuel. Imagine a crashing while landing with fuel tanks full....

Regards
Gerardo
dominguez(dash)online(dot)ch ... Pushing the limits of my equipment
 
MD-11 forever
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RE: Swissair/Air France Crashes - Why...

Tue Mar 20, 2001 12:24 am

Hello Gerardo

I agree with your opinion! The same people saying that they should have ignored the checklist and land with a plane far too heavy, would complain that they should have done the opposite.... It's nonsense to discuss this. I think the pilots made the right decisions according to the informations they had then. The point to question is, have they had enoug informations, if not, what would be necessary to prevent such a accident in future.

Regards, Tom
 
Ikarus
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Joined: Mon Jan 08, 2001 10:18 pm

RE: Swissair/Air France Crashes - Why...

Tue Mar 20, 2001 1:12 am

I have no direct knowledge of the situations - I quoted an article of the "Spiegel" (most serious German weekly newsmagazine) which argued that the emergency procedures have to be reviewed after this incident, as they were a contributing factor to the crash.

However, I am wondering: a plane landing far too heavy, what consequences would there be? Structural damage - probably. Collapse of Landing Gear? possibly, but I doubt it. Human fatalities? Only if landing gear collapses + plane breaks up or fire breaks out. Also, there would be emergency services immediately available, causing any loss of human life to be less than the 100% of a crash in the sea...

Can anyone confirm/rectify these guesses based on some technical info? I'd appreciate it!

Thanks

Ikarus
 
FDXmech
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Joined: Sun Mar 19, 2000 9:48 pm

RE: Swissair/Air France Crashes - Why...

Tue Mar 20, 2001 2:37 am

The MD11 is certified to land at MGTOW (max gross take-off weight) but is prohibited from performing an autoland above max landing weight.
You're only as good as your last departure.
 
pilot21
Posts: 983
Joined: Sun Oct 24, 1999 8:28 am

RE: Swissair/Air France Crashes - Why...

Tue Mar 20, 2001 3:21 am

In light of the SR111 crash, the procedures which have been recommended to all pilots is that if you have a smoke in the aircraft from an unknown origin, land the aircraft asap. I am not going to discuss the particulars of the Swissair crash because the crew did excatly what they were told in the checklist, however once the CVR's were reviewed, it was understood that these procedures cost valuable time.
Today, the understood rule is that if you have smoke, and you don't know where it is coming from, land the aircraft, IT WILL BE SAFER. Certain aircraft do have Max landing weights, but the chances of a gear going through the wing are quiet slim, as long as the pilot doesn't try to bounce the aircraft down the runway.

In regard to the Air France crash, the piece of metal on the runway (it is assumed at this stage) burst a tyre which sent peices of metal/tyre through the wing, bursting one of the fuel tanks/lines to engine 1/2. The leaking fuel was ignited by the afterburners, burning through the wing, cables and control surfaces. At the same time the engines were being starved of fuel which was being burnt before it reached the engines, thus power to 1/2 was lost. Coupled with limited flight controls, the aircaft started to pitch up and without 2 engines, stalled and crashed to the ground. (this has been the generally accepted version of events, however any further editions are very welcome)

Rgds

Pilot21
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