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Old 31st August 2012 | 19:06
  #922 (permalink)  
Lyman
 
Joined: Aug 2011
Posts: 2,074
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From: Grassy Valley
Dozy.

The photographic evidence of the VS/join FAIL tells the story. At the time, below 250 knots, the A300 Rudder was not limited. On the way down, the Rudder separated from the seven hinge points that attached to the Fin. It has always seemed shortsighted to spend so much time on a new system, and then forget to degrade one system, (e Rudder hinges) in favor of a far more critical one, the FIN JOIN. Any Trim device that can flat plate its mount to beyond critical load needs some serious reconsideration, which it got, the A350 Has seven (fourteen total) saddles/pins/tabs. The idea in engineering is to spread the load beyond failure territory. The Rudder hinges, the Saddle Pins, and the Steel saddles all survived the enormous Yaw 587 encountered. The Composite tabs broke like Ritz crackers. A simple solution would have been to "stack" two separate V/stabs, the upper one with weaker tabs, such that a portion of the V/stab remains if sideloads fail the top. It won't happen. Too unusual and expensive. No one would accept the "frangible" aircraft....

Cheers
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