Amateur-built T-51D N15180 accident near Ashtabula, Ohio

Probable cause

The tripped engine control computer circuit breaker caused by an excessive electrical load on the system, which resulted in a complete loss of engine power during the initial climb.

NTSB analysis

The intent of the flight was to perform fuel flow and fuel indicator checks on the newly built airplane while taxiing on the ground; however, they were not able to obtain full engine performance on the ground and the pilot elected to take the airplane into the air. After takeoff, while climbing through 200 ft above ground level (agl), the engine lost power. The operator reported that the engine computer circuit breaker had tripped which resulted in the loss of engine power. The pilot attempted to reset the circuit breaker and restart the engine without success. The airplane landed hard on the runway and the left main landing gear collapsed. The left wing sustained substantial damage.

A postaccident examination showed that the oxygen sensors used to tune the engine were left on the engine’s cylinder exhaust pipes during the flight. The sensors drew power from the engine’s control computer. During the initial climb, the increased electrical demand to run the oxygen sensors at maximum engine power exceeded the 15-ampere limit on the engine’s control computer, its circuit breaker to tripped, and the engine lost power.

Text from the NTSB. Open the NTSB docket for CEN21LA309 for the full record.