Incident Overview
A flight experienced a flight control malfunction shortly after takeoff, leading the crew to declare an emergency and return to the departure airport. The landing was completed without incident, and no damage to the aircraft or injuries to crew or passengers were reported. Total flight time was 6 minutes.
Captain's Account
According to the captain, after takeoff the aircraft began to yaw and roll in a cyclic fashion, alternating left and right. The captain attempted to rectify the issue by switching the yaw damper off and on to verify it was engaged. However, the yaw and roll continued and appeared to increase in yaw amplitude as airspeed increased. The captain declared an emergency and requested an immediate return to the airport, with emergency equipment standing by. The subsequent landing was performed normally.
Inspection Findings
The Stability Augmentation Computer, part number 2587826-3, serial number 0270890, was examined at the TWA Maintenance Facility. The inspection determined that the yaw rate gyro within the Stability Augmentation Computer had been installed in a reverse position, 180 degrees opposite from the correct orientation.