Accident Overview
During the initial climb following takeoff, the airplane experienced a partial loss of engine power. The pilot initiated a shallow turn toward the runway and verified that the throttle and propeller controls were forward. He then richened the mixture by two turns, but the airplane lost all ability to climb. A forced landing was executed in the desert, resulting in the shearing of the nose gear and one main landing gear, as well as bending of the propeller blades.
Pilot Actions
Prior to takeoff, during the initial engine run-up, the magneto check was not within acceptable limits. Approximately 15 minutes later, the pilot rechecked the magnetos and found them within acceptable limits. The pilot configured the airplane with 10 degrees of flaps and noted that all gauges were "in the green." He reported leaning the engine during taxi and takeoff. His leaning procedure involved bringing the mixture control back until the engine began to run rough, then turning the mixture control knob two times forward until the engine ran smoothly again.
Post-Accident Findings
A mechanic examined the airplane after the accident and found no discrepancies that would account for a loss of engine power. Approximately 20 gallons of fuel were present in the fuel system, and fuel was found in the fuel line to the engine. Passengers reported that the engine sounded normal but not as if it were running at full rpm during the initial climb. An aeronautical handbook states that operation with a lean mixture may result in a loss of engine power.