RV-9A N12VV accident near Missoula, Montana

Probable cause

The pilot’s improper fuel management, which resulted in fuel starvation and a loss of engine power. Contributing to the accident was the pilot’s failure to activate the auxiliary fuel boost pump, which inhibited a successful engine restart.

NTSB analysis

The pilot reported that he was performing flight testing after accumulating 9 hours of flight time on the recently constructed airplane. He departed with 16 gallons of fuel in the right tank and 8 gallons in the left tank. The pilot then flew for about 70 minutes with the fuel selector on the right tank. As the airplane approached the airport to land, a total loss of engine power occurred, and the pilot switched the fuel selector to the left fuel tank but did not activate the auxiliary fuel pump and his attempt to restart the engine was unsuccessful. The flight characteristics in the airplane’s final moments suggest the airplane entered an aerodynamic stall when it began a steep left turn and rapidly descended into the ground.

Postaccident examination of the wreckage did not reveal any preimpact mechanical anomalies with the engine or airframe that would have precluded normal operation. The pilot departed with about 15 gallons of usable fuel in the selected tank, and then flew for about 70 minutes. The engine was likely consuming fuel at a rate of about 12 gallons per hour (gph), which would have yielded a total fuel consumption of about 14 gallons during this flight. Fuel flow data indicated that the engine-driven fuel pump likely cavitated just before the engine lost power, which was likely caused by an unporting of the right fuel tank pickup due to insufficient fuel in the selected fuel tank. It is likely that the pilot’s improper fuel management resulted in fuel starvation and a loss of engine power. Further, the pilot’s failure to activate the auxiliary fuel boost pump likely inhibited the engine restart.

Text from the NTSB. Open the NTSB docket for WPR22LA231 for the full record.