scope:

Description of Driving Event:

The upper rudder of the 747SP aircraft was removed from the aircraft tail. The rudder was lowered lengthwise in the vertical position to a flat bed. The rudder was rotated to a position above the flat bed. The rudder was next rotated to a hinged up horizontal position. The two right hand fittngs were removed and the rudder was rotated over towards the right side. The lower left hand fitting pulled the screws and some surrounding structure from the rudder. This allowed the rudder to fall on the flat bed and then approximately 30 inches to the concrete floor.

One area 8 inches by 5 inches of the rudder frame and skin was pulled loose. One threaded lock was pulled loose and one threaded lock was stripped. Several rivets were popped on one of the counter weight attachments and minor bending on the lower end of the rudder.