On August 12, 1983, a Cessna 310Q (registration N69JM) was involved in an aviation accident near Scranton, PA. Investigators recorded the probable cause as: Improper routing of the condenser wire that exposed it to the magneto drive, resulting in a short. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An aircraft observed making a left 360-degree turn after takeoff struck a house. The pilot did not respond to controller calls. Investigation revealed a magneto wire short due to improper routing.
Accident Summary
Shortly after takeoff, an aircraft was observed on radar making a left 360-degree turn. The pilot did not respond to a call from the air traffic controller. A witness reported hearing the plane "sputtering" and observed it performing erratic maneuvers before it struck a house.
Investigation Findings
A post-accident examination of the aircraft's left engine revealed that the left magneto did not produce any spark during a functional check. Upon disassembly, the condenser wire shielding was found partially cut and had shorted against the magneto drive. Investigators determined that this condition resulted from improper routing, which exposed the wire to the magneto drive.
Inspection History
The aircraft and its engines had an annual inspection completed on August 10, 1983.
Probable cause
Improper routing of the condenser wire that exposed it to the magneto drive, resulting in a short.