Re: Are Two Engine 757 & 767 Jets Dangerous?

Date:         13 Dec 96 04:26:00 
From:         kchao@acsu.buffalo.edu (Kuang-Chng Chao)
Organization: University at Buffalo
References:   1
Followups:    1
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In article <airliners.1996.2811@ohare.Chicago.COM>,
Karl Swartz <kls@ohare.Chicago.COM> wrote:
...snip
>
>The big question is what happens when both engines on one wing fail.
>The certification requirements require that you be able to take off
>and climb if *one* engine fails after reaching V1, but what about
>a double failure?  I assume you have to handle this in cruise since
>the pre-ETOPS ICAO rules for long overwater flights mandated the
>ability to limp to safety after the loss of two engines, but losing
>two at cruise, with relatively low thrust levels is a very different
>matter from losing two during takeoff or climb, at high thrust levels.
>
>The El Al crash in Amsterdam, as well as the 1991 China Air crash near
>Taipei (both 747-200Fs) suggest that losing two during climb may not
>be recoverable -- I'm not sure if any of the wing damage in El Al was
>significant with regard to control of the plane, and I know even less
>of the details of the China Air crash.
>
>On the other hand, United 811, the 747-100 which lost the cargo door,
>shows that a 747 *can* recover and return safely after losing two
>engines at higher altitudes (though in that case still during climb).

In both El Al and China Air cases, two engines on the same side separated
from the wing, not just lost power. United 811 lost power but the engines
still hang on. A pilot friend told me, El Al was marginally recoverable
from simulator study in the investigation, had the pilots knew the engines
were gone. No official report of China Air was ever released as far as I
knew. My pilot friend, a 744 FO, suspected with more weight, the pilots of
China Air had no chance even with the control intact. How heavy was UA 811?
China Air was near MGTOW, El Al was somewhat lighter, sorry I don't have any #.


my 2 cents

kc