Incident Description
The pilot reported that while on the downwind leg, he turned on the auxiliary fuel pump, switched the fuel selector to the fullest tank, and then turned the auxiliary fuel pump off. On final approach at 400 feet, he deployed the flaps and attempted to increase engine power but received no engine response. After performing emergency procedures without success, he executed a forced landing. The airplane nosed over in a muddy field following the landing.
Investigation Findings
Post-incident examination of the airplane revealed an out-of-rig condition in the throttle-related system that automatically controlled the two-position/pressure auxiliary fuel pump. An engine ground run conducted before re-rigging the system showed an over-rich fuel mixture and rough engine operation at idle. When the throttle was advanced beyond one-third, the engine would not run. After the system was re-rigged to correct the out-of-rig condition, a subsequent engine run demonstrated normal operation.
Pilot's Checklist Reference
The pilot's checklist includes the item 'Auxiliary fuel pump - OFF,' which appears three lines after the item 'Fuel selector valve - FULLER tank.'