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Old 16th May 2010 | 17:05
  #1069 (permalink)  
bearfoil
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The report states the RTLU was removed and tested; it was found to be "stopped" at 4 degrees each side of center.

The obvious question, the Rudder is shown to be @ 40 degrees right in at least one photograph, and similarly positioned in another, these taken while in the sea, and after removal from the sea. In the chain of recovery, why is the rudder at such an angle? There is nothing in the report to explain this apparent discrepancy. If the RTLU FAIL was accurate, is it assumed that it would revert to its 'protect' position, though Fail was on the screen? At .82 Mach and an unrestricted Rudder in Alternate Law II, the danger is clear. Why is the vertical pick up arm fractured, but the Rudder hinges seem servicable? With 35 degrees of sweep "available", this arm would be tortured in virtually any plane, but most importantly (here) in the plane it was supposed to protect, (maneuvering).

About the Lateral defensive Rods. These parts, actually resembling straps more than rods, appear to have been subjected to above fail limits, as their mounts and structural integrity have been completely lost. Their position and posture on the mounting rail shows complete failure. This is indicative of Fail Plus loads in the lateral plane, a stress the report ignores in its march toward "Vertical only" stresses.

One last thing. The Female lugs have sheared in the area between structural webbing and uniform build up at the mount hole. Vertical loading would absolutely not shear these structures in this area from translated vertical loads. An extreme "bend" or "radial" resistance would be the only mechanism to cut these parts in two in this region. One would expect a failure at the lug insertion point with sufficient vertical energy. This is replicated at the vertical pick up arm, where the "end" snapped off due to vertical loading, a kind of stress that was designed for, ie Rudder loads in each direction.

Consider. The lateral rod mount, a rail between the lugs, is not shown to be deflected in the vertical. Yet the rods are destroyed. They failed in lateral, a failure consistent only with aerodynamic loading.

Consider. The vertical pick up arm failed in designed for expression. It is meant to keep the Rudder in longitudinal conformity with the VS. It performed. The eight rudder hinges show no damage, as evidenced by the Rudder's free movement at recovery.