Incident Overview
An aircraft experienced a loss of engine power shortly after takeoff, necessitating a forced landing on a residential street. The engine had undergone an overhaul at an FAA-certified repair station five months and 150 flight hours prior to the incident.
Examination Findings
Post-incident inspection of the engine magneto disclosed internal corrosion and electrical arcing at the breaker points. Additionally, the insulation on the 'P' lead wire was found to be cracked along its entire length, exposing bare wire at one location. Investigators noted that grounding of the 'P' lead, resulting from the bare wire contacting the airframe, would produce an effect identical to placing the ignition switch in the off position.
Conclusion
The condition of the magneto and the compromised 'P' lead wire insulation were documented as part of the examination. No further analysis or causal statements are provided in the source material.