RE: Tristar FMC

From:         hedleyj@wl.aecl.ca
Organization: MIT PLASMA FUSION CENTER
Date:         21 Dec 94 02:17:41 
References:   1 2
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Alain Arnaud (ecla@world.std.com) wrote:

>As I recall, the L1011-500 had an active stability system, which
>meant that the aircraft was basically unstable and required computer
>control of the ailerons for safe flight.  In the late 70's this was
>way ahead of anyone else in the industry was doing and certainly
>a precursor of the active controls in the Airbus family and closer
>to Lockheed in the F117.

This is incorrect.  The active control system in the Tristart 500
sensed loads on the wings and deflected the ailerons in such a manner
as to keep the lift vector pointing as nearly "straight up" as possible.
This improved the cruise performance of the wing somewhat, and, by
"dumping" loads outwards along the wing to the wingtip reduced a/c
response to gusts and/or rough air, offering a smoother ride.  Whether
or not passengers were actually able to notice this, I don't know.
(Sorry, :-), that should be _Tristar_ 500 !)


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Bruce Hedley                   |
AECL Research                  |
Whiteshell Laboratories        |  " Nostalgia isn't what it used to be "
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<hedleyj@wl.aecl.ca>           |
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