NTSB Identification: SEA98LA120.
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Accident occurred Saturday, July 04, 1998 in DRIGGS, ID
Probable Cause Approval Date: 02/11/2000
Aircraft: Beech D35, registration: N3469B
Injuries: 3 Uninjured.
NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
The pilot reported that while preparing for landing, he turned on to the base leg and reset the mixture, propeller and throttle controls to full forward. At this time the engine experienced a complete loss of power. The pilot attempted to restart the engine with no success. Due to the low altitude, the pilot felt that he could not make it to the runway and opted to land on a dirt road. During the landing roll, the left wing collided with a fence post. Post-crash inspection of the engine found that the spark plugs for two of the cylinders were 'fouled,' and that the piston heads for these cylinders were black and displayed excessive carbon build-up. The fuel metering unit was bench tested. During the test, it was found that at the high RPM setting, both the fuel pump pressure and the fuel flow pressure were excessively out of limits. It was also noted that contamination that appeared to be 'rubber' or a 'gasket-like' material was found on the fuel control valve, and the manifold valve screens. This substance was also found under and around the seat area on the fuel pump. Large amounts of 'particles' were also found inside the pump return fitting.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: Excessive pressure in the fuel control unit. A foreign material/substance found on the fuel system screens was a factor. Full narrative available
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