Technical Computer Services

Rockwell Aero Commander 685

While turning from downwind to base leg, the aircraft was observed descending rapidly in a steep bank. Witnesses reported smoke was trailing from the aircraft. The aircraft crashed in an industrial area. An exam of the right engine revealed that the exhaust-to-turbo adapter, pn 641829, had fractured and separated. The fracture was a result of thermal fatigue and it had propagated across more than 95% of the area before final separation had occurred. Since an exam of the cowling and both engines showed no streaking heat or smoke patterns, the reported 'smoke' was attributed to exhaust gas. While there was a loss of power in the right engine, no other aircraft malfunctions were found that would have caused loss of control. All six occupants were killed.