What happened
On 1 July 2000, a PA 28R-180 aircraft, registered ZS-FVH, was involved in an accident during a training flight at Bethlehem Airport. Earlier that day, the aircraft had been moved to a maintenance facility to replace a fuel booster pump following reports of engine roughness.
During the pre-flight inspection for the scheduled training session, the pilot noted abnormally high fuel pressure but did not investigate the issue further. During taxiing, the engine appeared to operate normally with the fuel booster pump deactivated. At the holding point, the pilot performed power checks and found all indications to be within limits. After lining up on the runway, the pilot activated the fuel booster pump and applied full power against the brakes for an extended period to verify system functionality.
Following take-off, the fuel flow became unstable, fluctuating wildly between 12 Gal/hr and 0 Gal/hr while the booster pump was active. This instability was followed by a total engine failure, leading to the aircraft crashing at the airport. There were no fatalities and no injuries resulting from the impact.
The investigation
Investigators examined the aircraft's fuel system and electrical components following the crash. They discovered that the circuit breaker for the fuel booster pump had tripped during the accident. Upon resetting the breaker, the engine was able to start and run normally; however, the engine failed again as soon as the fuel booster pump was turned off.
Technical inspections of both the fuel booster pump and the engine-driven fuel pump confirmed that both components were in serviceable condition. However, the investigation identified that the circuit breaker for the fuel booster pump was defective.