PPRuNe Forums - View Single Post - Big Crash at Reno
View Single Post
Old 28th Sep 2011, 00:21
  #207 (permalink)  
Lyman
 
Join Date: Aug 2011
Location: Grassy Valley
Posts: 2,074
Likes: 0
Received 0 Likes on 0 Posts
#207

With asymmetric elevators (by aspect), and at 450mph, I am going to say the tail section rotated (twisted) counter/clockwise as seen from aft. This would cause the additive roll left of the airframe. This explains the additive left roll that made vertical the wings as explained elsewhere caused by W/T. The buckles show this torsional aspect in concert with a Yaw and "drop" of the tail, meaning that the more emphatic elevator was the right one, and if it imparted a down force, it meant the tabs were "up", at the time the left tab was lost. this is consistent with carrying a Nose Down bias in the circuit.

That area of the airframe is hardly what one could call "stressed skin" so the damage is not particularly surprising, as it results from a structural failure in a design consideration that needn't have been addressed.

A secondary analysis might include the buckling resulted from a massive Nose Up input. With the elevators trending up, the tail would would endure a great download, a longitudinal collapse downward could have produced the 'extra' skin necessary to produce the wrinkling.

A combination of both mechanical issues is also possible.

Last edited by Lyman; 28th Sep 2011 at 00:37.
Lyman is offline