Where is the Horizontal Stab? Could a failed pitch trim mechanism have caused this. AKA Alaska 261. If the attachment point fails, could this cause the horizontal stab leading edge to go full up, causing the plane to nose down, then at some point the aerodynamic forces cause it to go the other way causing a climb, and on and on until it fails completely and departs the airplane. If the tail had departed because of a pressure bulkhead failure, the horizontal stab should have remained with the rest of the tail section... then again maybe not.