Event Description
Approximately 30 minutes after departure, the aircraft returned to the airport trailing smoke and occasional flame from an area near the cowl flaps and nose gear doors. The pilot did not make a straight-in approach but appeared to be flying a normal traffic pattern. The aircraft stalled where a left base leg turn would have been made.
Evidence of Fire and Oil Leakage
Inside the cockpit, there was evidence of heat and smoke. The broken windshield had sooted interior portions. The underside of the empennage was covered with fresh oil over its entire length. Oil stains and fresh oil leakage signatures were present on the oil drain housing attached to the accessory case. The rear clamp was loose on the P/N 24827 hose that couples this housing to the intake and oil drain manifold.
Aircraft Modifications
The aircraft was extensively modified by the owner between October 1979 and the date of the accident. No FAA Form 337 (Major Repair and Alteration) had been filed since May 14, 1975, even though a large engine and numerous modifications to the aircraft had been accomplished by the owner.