Incident Overview
Description
The Dornier 228-100 prototype, registration D-IFNS, was destroyed when it crashed during a test flight. All three crew members, a Dornier test pilot and two U.K. CAA pilots were killed in the accident. The flight was part of the UK Civil Aviation Authority’s certification programme for the type. It took off from Oberpfaffenhofen Airport (OBF) at 17:27. During the flight the aircraft was trimmed into a full nose down position to simulate a horizontal stabilizer trim-runaway. Both pilots were unable to maintain pitch control due to the excessive stick forces. For unknown reasons a retrim could not be initiated. The aircraft disintegrated in a nose down attitude about 1200 ft agl. Stick forces in excess of 50 deca-newton were pulled to counteract the mistrimmed condition. this disengaged the pitch trim actuator clutch preventing any stabilizer movement in nose-up retrim attempts. The pilot may have been distracted by the need to communicate with the telemetry station. On becoming aware of the critical flight situation he assisted the other pilot on the controls, but by this stage their joint strength was insufficient to effect recovery.
Primary Cause
Excessive stick forces during a trim-runaway maneuver caused by the aircraft’s instability.Excessive stick forces during a trim-runaway maneuver caused by the aircraft’s instability.Share on:
