Taylorcraft BC12-D N95078 accident near Trojan, South Dakota

Probable cause

The partial loss of engine power due to a loose magneto and subsequent impact with terrain.

NTSB analysis

The pilot reported that while enroute the engine sustained a partial loss of power. The pilot attempted to restore engine power by applying carburetor heat, adjusting the mixture, and checking the fuel control valve. The pilot’s troubleshooting efforts were unsuccessful, and the airplane was unable to maintain altitude. The pilot descended into a wooded valley and conducted a forced landing into the treetops. The airplane came to rest inverted and sustained substantial damage to the fuselage and both wings.

Postaccident examination of the engine revealed that the hold-down nuts on the right magneto were loose, and the magneto could rotate freely by hand. It is likely that the loose magneto detrimentally affected ignition, which resulted in a partial loss of engine power.

Text from the NTSB. Open the NTSB docket for CEN24LA341 for the full record.