What happened
While cruising at flight level 250, the aircraft's engine stopped operating. The failure was attributed to a malfunctioning fuel pump. Despite the loss of power, the crew managed to restart the engine successfully when the aircraft had descended to 10,000 feet mean sea level. Following the restart, the flight continued with no further issues and concluded with an uneventful landing.
The investigation
Examination of the failed component revealed that the fuel pump was a Model G unit with only three hours of total time in service. This specific pump had been installed as a replacement for a previous Model C fuel pump, which had failed earlier due to a crack in its aneroid bellows.
Findings
The investigation determined that the Model G fuel pump failed because manufacturing tolerances were too close. This tight tolerance likely contributed to the premature failure of the component during operation.