Accident Overview
The airplane collided with the ground and obstacles following a loss of engine power during takeoff. Witnesses reported that the engine lost power during the takeoff roll, after which the airplane entered a sharp right bank before colliding with obstacles and terrain.
Post-Accident Examination
A post-accident examination of the engine revealed that debris coated the inlet side of the fuel manifold valve. The manifold valve is designed with a screen separating the inlet side from the outlet side; fuel enters through the screen and exits to the fuel injector nozzles. The debris on the inlet side prevented fuel pressure from reaching specifications. The injector fuel pressure could not be obtained above 213 psi, while the specification called for 250 psi. Additionally, the fuel pump pressure measured 83 psi, exceeding the specified 32.5 psi. At engine speeds above 1,500 RPM, the fuel pressure may have been excessive, depending on how the debris was distributed within the valve.
Pilot History
An aviation maintenance technician and a family member reported that the pilot had been experiencing engine trouble during takeoff on previous occasions, similar to the circumstances surrounding the accident. To correct the problem, the pilot would adjust the mixture setting. This adjustment was most likely made in response to the excessive fuel pressure at the pump, which was set as a result of the low fuel pressures due to the contaminated manifold valve. As the system pressure increased, the debris generally limited the fuel flow pressure; however, because the debris could move within the valve, the pilot most likely experienced erratic fuel flow pressures.
Maintenance Records
No maintenance entry was found for the adjustment of the fuel pump, nor was any maintenance of the manifold valve noted. Both components had been remanufactured during an engine overhaul approximately 6.5 years prior to the accident.