The private pilot, who was the builder of the Bede BD-5B, said the purpose of the test flight was to obtain rate of climb data on the airplane, which had recently been completed.
Following the sixth climb of the flight, the engine began to run rough. The pilot turned back toward the airport and entered the traffic pattern, and the engine experienced a total loss of power.
The pilot determined that the airplane would not reach the runway and performed an off-airport landing in a field near Portland, Indiana. The field was soft and contained high vegetation, which resulted in a ground loop during landing.
The pilot noted that, during the flight, the No. 1 cylinder exhaust gas temperature and cylinder head temperature had dropped, indicating that the No. 1 cylinder was not firing properly. It was after the No. 1 cylinder quit firing that the No. 2 cylinder also quit firing.
A postaccident examination of the engine revealed that the wire in the No. 1 cylinder connector between the engine control unit and the fuel injector was not properly crimped at the connector, which allowed the wire to be pulled back.
In addition, a wire to the No. 2 connector was found broken where the wire had been spliced. This wire most likely separated at the spliced area due to engine vibrations after the No. 1 cylinder ceased operating.
Probable cause: A failure of the wiring between the engine control unit and the fuel injector, which resulted in a total loss of engine power.
NTSB Identification: CEN17LA205
This May 2017 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
As an electrical engineer , pilot and aircraft owner, I’ve seen a lot of wiring failures on both experimental and certified aircraft. The majority of these wire failures are fatigue failures at the connection crimp.
The fatigue failures are primarily due to the lack of proper stain relief within 2 inches of the connector/connection. Vibration from the engine is the cause of the fatigue / work hardening of the wires.
I’ve seen most of the wiring failures at the alternator, voltage regulator and master contactor. All of which can cause a ‘total loss’ of electrical power.