Accident Sequence
During a flight, the Cessna 120 experienced a complete loss of engine power. The pilot attempted to return to the departure airport, but the airplane collided with trees.
Pilot Actions and Fuel Management
The pilot stated that he had not visually checked the fuel quantity in the tanks prior to departure. However, the right fuel tank gauge indicated 1/4 full. The pilot also noted that the fuel gauges were unreliable. When asked about checklist usage, he reported that he did not use a written checklist but had gone through a mental one before takeoff.
The pilot normally flew a Cessna 180, in which the middle position of the fuel selector is used for both tanks. On the Cessna 120, however, the middle position selects only the right tank.
Post-Accident Examination
No evidence of preimpact mechanical failures was discovered. Examination of the fuel system revealed fuel present in both fuel tanks, the primer was unlocked, and the left fuel gauge indicated 3/8 full. The fuel selector was found in the "off" position. The mechanic who first responded to the accident site could not recall whether he turned the fuel selector to "off" or if it was already in that position.
According to the Cessna 120 Owners Manual, the pilot should set the fuel tank selector to the fullest tank for takeoff and should not take off on less than 1/4 tank.