From Owain,
2. At that sort of AoA the rudder power would be severely limited because (a) it was working at something like 70 deg effective sweep and (b) it was probably sat in the low energy wake of the stalled wing.
Pursuant to your observation, I would like to add that the Rudder/Vstab may have had little if any directional control as a system, and that the Rudder may have had an opposite effect to control deflection.
Would you rule out that Rudder may have reversed its effect, if not wholly, then intermittently?
The Rudder, at 17 degrees sweep from vertical, plus AoA, supplies just the sort of tangential bias from airflow from under the HS and even behind it, at this point? That the airflow past Rudder in this direction works opposite its intended force? Keeping in mind that the elevators, fully UP, do not shield this surface from under tailplane flow?
The Directional system is also in a transiently Stalled wake, that of the HS/elevators?
Perhaps off the wall, but the corner of the Rudder that exhibited damage was in this very unusual flow, and in effect, played leading edge to V/S system, collecting its drag from beneath and behind the HS/elevators? As such, it would be in vulnerable and undesigned for airflow, perhaps in some sort of leading edge flutter that corrupted the structure as seen in early photos?
Last edited by Lyman; 19th May 2012 at 17:14.