CEN19LA326

Just after takeoff following a touch-and-go landing, the engine backfired and lost partial power. The pilot decided that he could not land on the remaining runway, so he continued to climb the airplane, raised the flaps, and increased airspeed. The manifold pressure continued to decrease despite the pilot’s application of full throttle, and the pilot attempted to return to the airport, but had insufficient altitude, and conducted a forced landing to a field. The nose landing gear sheared off, and the main landing gear collapsed. Both wings sustained substantial damage. Examination of the engine and accessories revealed that the left magneto fired on only 3 of its 6 terminals. The airplane was equipped an electronic ignition system that was coupled to the magnetos. The system created multiple sparks over a longer duration and synchronized timing between the two magnetos. This synchronization was accomplished by using the left magneto as a trigger for the complete system. When the electronic ignition was operating, it relied solely on the left magneto points to fire both magnetos with an enhanced multi-spark. If the left magneto failed or deteriorated, then the complete ignition cycle would be compromised. The degraded functionality of the left magneto was likely the cause of the partial engine power loss.

On September 20, 2019, about 1940 central daylight time, an experimental, amateur-built RV-10 airplane, N569JC, sustained substantial damage when it was involved in an accident near Lancaster, Texas. The airline transport pilot and three passengers were not injured. The airplane was operated as a Title 14 Federal Code of Regulations Part 91 personal flight. The pilot reported that the 40-minute flight was uneventful until he conducted a touch-and-go landing. During the initial climb, the nosewheel sounded like it was vibrating, and the engine backfired and lost partial power. The pilot decided that he could not land on the remaining runway, so he climbed the airplane, raised the flaps, and increased airspeed to 95 to 100 knots. The manifold pressure was dropping from 17 to 14” with full throttle and the engine power continued to decrease. The pilot decided to try a gentle turn toward the airport before realizing that he did not have adequate altitude, and instead conducted a forced landing to a field, during which the nose landing gear and main landing gear collapsed. Both wings sustained substantial damage. All occupants exited the airplane. The airplane was recovered to a secure facility for examination. Teardown examination of the engine did not reveal any mechanical anomalies. The fuel system was intact, and no obstructions or leaks were observed. The magnetos were bench tested. The right magneto displayed no anomalies. The left magneto fired on 3 of the 6 terminals. The airplane was equipped with a G3i electronic ignition system that was coupled to the magnetos. The system created multiple sparks over a longer duration and synchronized timing between the two magnetos. This synchronization was accomplished by using the left magneto as a trigger for the complete system. While the electronic ignition was operating, it relied solely on the left magneto points to fire left and right magnetos with an enhanced multi-spark. If the left magneto failed or deteriorated, then the complete ignition cycle would be compromised.