Incident Overview
The aircraft taxied from the terminal building to runway 36 and took off without clearance from either ground or local control. Controllers attempted to halt the aircraft using a red light gun signal, but the airplane did not stop. The controllers did not see the airplane stop in the run-up area.
Flight and Impact
Witnesses, including an FAA airworthiness inspector, reported that just beyond the departure end of the 5,000-foot runway, the airplane began a tight left turn, as if attempting to return to the runway. The left bank increased until the nose dropped and the airplane descended vertically to ground impact, about 1,000 feet from the approach end of runway 18. The FAA inspector observed a trail of smoke coming from the airplane during the initial climb.
Preflight and Maintenance
The pilot ordered fuel about one hour before takeoff and supervised the process; 15 gallons were added to each tip tank and none to the main tank. No determination could be made as to the quantity in the main tank at departure. The pilot pointed out two empty oil cans lying on the ground by the airplane's nose and asked the refueler if he could throw them away. The refueler did not observe the pilot placing oil in the engine or completing any other aspect of a preflight inspection. The pilot held an A&P certificate and performed all maintenance on the aircraft. Maintenance records documented an unresolved oil consumption rate of 1 pint per hour over the previous 10 months. The pilot's personal flight logbook reflected that between 1989 and the accident, the pilot had flown 100 hours total, all in the accident airplane. The most recent six months of activity consisted of three flights in April, two in May, and two in July.
Fuel System Examination
The aircraft fuel system consisted of a main fuselage tank (capacity 39 gallons) and left and right tip tanks (each 34 gallons). The pilot operating handbook stated that for starting, takeoff, and climb, the fuel selector should be selected to the main tank and the electric fuel boost pump should be used for takeoff and when switching fuel tanks. Examination revealed no hydraulic deformation to the ruptured main fuel tank and no fuel found in the tank. All vent lines and ports for the fuel tanks were clear and unobstructed. The fuel selector was visually examined; the ball cock opening was found positioned between the main tank and the left tip tank, with the opening about 40 percent open to the left tip and about 10 percent open to the main tank. The electric fuel boost pump switch was in the OFF position. Fuel gauges showed 3/4 full for both tip tanks and 9 gallons for the main tank.
Cockpit and Engine Examination
The avionics master switch was in the OFF position. The No. 1 communications radio was selected to 125.1 (local control frequency), while the No. 2 communications radio was on 121.1. For the audio control panel, the transmitter was selected to No. 1 and the speaker to No. 2. Borescope examination of cylinder interiors revealed deposits of rust on the cylinder walls. No other preimpact anomaly was found during an examination of the engine or airframe systems.