What happened
Following takeoff and reaching a level altitude, the pilot experienced an engine malfunction and began an immediate return to the airfield. Within two minutes of the initial malfunction, the pilot reported an engine fire and declared an emergency. Shortly after this declaration, the right wing detached from the aircraft type, resulting in a crash.
The aircraft was occupied by the pilot, who was the sole occupant and was killed in the accident.
Findings
An investigation of the wreckage identified significant fire damage near the area where the wing separated. Investigators discovered a hole measuring 2.5 by 3 inches in the right inboard exhaust tube (pn 0850712-6). This breach was positioned toward the accessory compartment, where various fuel and oil lines showed signs of charring and fire damage. The examination further revealed that the engine support structure and the wing spar had melted due to the intense heat.
The inspection of the exhaust tube indicated that the metal walls were thin, brittle, and discolored at the site of the rupture, with multiple cracks and small holes present. At the time of the accident, the exhaust tube had accumulated 5,862 total service hours, with 1,762 hours logged since its last overhaul. While records indicated compliance with AD 75-23-08 during an inspection 25 flight hours prior, the corroded exhaust system was identified as a primary factor in the failure.