LAX01FA011 · Navion G

The aircraft collided with the ground in a near vertical nose down descent during an attempted return-to-runway maneuver in the takeoff initial climb. The airplane taxied from parking at the terminal building to runway 36 and took off without a clearance from ground or local control. Both controllers attempted to stop the airplane by using a red light gun signal control; however, the airplane did not stop. The controllers did not see the airplane stop in the run-up area. Other witnesses, including an FAA airworthiness inspector reported that just beyond the departure end of the 5,000-foot-long runway, the airplane began a tight left turn, as if attempting to return to the runway. The left bank continued to increase 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 saw a trail of smoke coming from the airplane during the initial climb. The pilot ordered the fuel about 1 hour prior to takeoff and supervised the process; 15 gallons were put in each tip tank and none was added 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 laying on the ground by the airplane's nose and asked the refueler if he could throw them away for him. The refueler did not observe the pilot placing the oil in the engine or complete any other aspect of a preflight inspection. The pilot, who is an A & P, performed all maintenance activities on the aircraft. Notations in the maintenance records show an unresolved 1-pint per hour oil consumption rate over the last 10 months. The pilot's personal flight logbook reflected that between 1989 and the date of the accident, the pilot had flown 100 hours total, all in the accident airplane. The most recent 6 months of activity consisted of three flights in April, two flights in May, and two flights in July. The aircraft fuel system consists of a main fuselage tank (which extends into the root area of each wing), and a left and right tip tank. The main tank has a capacity of 39 gallons, and each tip tank has a 34-gallon capacity. The normal operating procedures section of the pilot operating handbook states that for starting, takeoff and climb, the fuel selector should be selected to the main tank, and that the electric fuel boost pump be used for takeoff and when switching fuel tanks. No hydraulic deformation was noted to the ruptured main fuel tank, and no fuel was found in the tank. The vent lines and ports for all three fuel tanks were clear and unobstructed. The fuel selector was visually examined by looking in the ports for each of the tanks. The ball cock opening was found positioned between the main tank and the left tip tank; the opening was 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. The fuel gages showed 3/4 full for both tip tanks and 9 gallons for the main tank. The avionics master switch was in the OFF position. The No. 1 communications radio was selected to 125.1 (the local control frequency), while the No. 2 communications radio was on 121.1. For the audio control panel, the transmitter was selected to the No. 1 communications radio and the speaker was selected to the No. 2 communications radio. Borescope examination of the cylinder interiors revealed deposits of rust on the cylinder walls. No other preimpact anomaly was found during an examination of the engine or the airframe systems.

Verbatim NTSB analysis and probable cause from the NTSB dataset