LAX08LA064 · Cessna 210

The student pilot and passenger departed on the cross-country flight with both wing fuel tanks about 3/4 full. During the pilot's first attempt to land, the airplane was too high and he decided to perform a go-around. On his second attempt, the airplane was configured on final approach with the flaps fully extended and the landing gear down. As the airplane was approaching the runway at an altitude of 400 feet above ground level (agl), the engine experienced a loss of power. The airplane touched down short of the runway and the right wing collided with a small tree during the landing roll. An engine examination revealed that the spark plugs were heavily sooted, indicative of a rich mixture. Mechanical continuity was verified with rotation of the crankshaft. The ignition harnesses and the P-leads exhibited excessively worn insulation and shielding. Following an unsuccessful attempt to run the engine, both P-leads were found to be broken at a pass through hole in the engine baffling. The broken P-leads were spliced together and a second attempt to start the engine was made; the engine started and ran roughly at low power settings, smoothing out at higher ranges, though still notably rough. A magneto check revealed that the left magneto was not functioning. Troubleshooting the wiring revealed that only intermittent continuity could be established in the wiring between the ignition switch and the magnetos, resulting in intermittent grounding.

Verbatim NTSB analysis and probable cause from the NTSB dataset