Accident Sequence
The aircraft experienced a loss of engine power during the initial climb after takeoff. Ground witnesses reported that the airplane reached approximately 100 feet of altitude before the engine coughed and lost power. The pilot subsequently made a "flat and hard" landing off the end of the runway, and the airplane slid into a creek bed.
Pilot Actions and Witnesses
The pilot stated that before takeoff he had run the engine up using the tip tanks. After confirming smooth engine operation, he switched to the left main tank for departure. When the engine coughed and quit, he activated the electric auxiliary fuel pump and verified he was operating on the left main tank, but did not have time to attempt a restart.
Post-Accident Inspection
A California Highway Patrol pilot officer, the first to arrive at the scene, turned the tip tank fuel selector valve from the LEFT to the OFF position. An FAA inspector later examined the selector panel and found the main fuel valve positioned to the right main tank; however, fire department personnel had reported moving several switches and levers to secure the cockpit.
Fuel Documentation
Fuel tank documentation revealed the left main tank contained about 7.5 gallons, the right main tank about 5 gallons, the left tip tank was empty, and the right tip tank was destroyed. No fuel leakage was observed on the ground beneath the left tip tank. The fuel supply line to the carburetor was loosened, and approximately one tablespoon of fuel was recovered from the line.
Manufacturer Guidance
The Owner's Manual states that "in no case should a takeoff be made if the fuel indicators are in the yellow band or, with less than 10 gallons of fuel in each of the main tanks." According to Raytheon Aircraft, this warning is due to the location of the fuel pickups in the tanks on this model aircraft, which could allow unporting and fuel supply interruption during steep attitudes, turning-type ground maneuvers during takeoffs, or uncoordinated flight.
Engine Testing
After the aircraft was recovered to a salvage yard, the engine was mounted on a test stand. It started on the first attempt and accelerated smoothly, with normal throttle response and magneto operation.