Amateur-built MODEL 12 N512P accident near Conroe, Texas

Probable cause

The failure of the engine-driven fuel pump, which resulted in a total loss of engine power. Contributing to the failure of the fuel pump was an unknown non-ferrous metallic debris that was noted throughout the airplane’s fuel system.

NTSB analysis

The pilot and passenger were conducting a local flight to practice maneuvers and landings. About 3 to 4 minutes after takeoff, and 2,000 ft above ground level, the pilot noticed a master warning light on instrument panel but did not notice any anomalies or problems. The pilot elected to return to the airport, and about 1 minute later the engine sustained a series of power loss fluctuations. The pilot attempted to troubleshoot the problem but was unsuccessful and the engine lost total power. Unable to reach the airport or a field due to a high descent rate, the pilot performed a forced landing to a nearby roadway. During the landing, the airplane impacted a powerline and terrain before coming to rest inverted. The airplane sustained substantial damage to the wings, fuselage, and empennage.

Postaccident examination of the airplane revealed non-ferrous metallic debris throughout the entire fuel system; the source of the debris was unable to be determined. Due to a leak noted during a functional test, the engine-driven fuel pump was disassembled. Scratches and scoring marks were noted on the pressure relief valve seat, which allowed fuel into the air side cavity of the fuel pump. It is likely the fuel pump air cavity filled with fuel, which equalized the pump pressure and restricted fuel flow to the engine. The restricted fuel flow resulted in a total loss of engine power.

Text from the NTSB. Open the NTSB docket for CEN23LA081 for the full record.