Originally Posted by airsupport
Someone MAY have exerted excessive pressure on the tail in a desperate attempt to fly the Aircraft, which ultimately caused the tail to fail, HOWEVER it was just a matter of time before something happened as the tail assembly was weakened by this continual trapped water
When a tail assembly fails at 1.93 times Limit Load, then it is 29% over certification strength (which is 1.5 times Limit Load). It is inappropriate to call it "weakened". One could more accurately call it "overbuilt".
Originally Posted by 411A
The fact remains of course that the concerned airline operator had a program of aggressive maneuvering in place (or just before)
The operator was warned in 1997 by a joint letter from the FAA, Boeing and Airbus:
Originally Posted by FAA/Boeing/Airbus letter to AA
The excessive emphasis [in AAMP] on the superior effectiveness of the rudder for roll control ... is a concern. Rudder reversals such as those that might be involved in dynamic maneuvers created by using too much rudder in a recovery attempt can lead to structural loads that exceed the design strenght of the fin and other airframe components. The hazard of inappropriate rudder use during windshear encounters, wake turbulence .... should also be included in the discussion.
In other words, the regulator and major airframe manufacturers warned explicitly of the events that happened to AA587 some four years before.
This is considered in Section 3.5 of my paper "The Crash of AA587: A Guide" from November 2004, available from
http://www.rvs.uni-bielefeld.de/publ...ashOfAA587.pdf
Importantly, trying to control roll with rudder has dynamic characteristics which lead to oscillatory behavior in all large transports. This is inherent. For this reason and others, the BEA does not consider rudder to be a primary flight control.
There are lots of other things to be said about this accident; I said most of what I think are worthwhile to say in the paper cited above.
PBL