Piper PA28 N8441B accident near Santee, California

Probable cause

The pilots' failure to maintain airplane control following a partial loss of engine power after takeoff, which resulted in an aerodynamic stall. Contributing to the accident was the partial loss of engine power due to a failure of the right magneto.

NTSB analysis

The flight instructor and student pilot were conducting touch-and-go takeoffs and landings in the airport traffic pattern. While on the upwind leg of the traffic pattern following the second takeoff, the airplane entered a steep left turn and impacted a residential area; a postimpact fire ensued. One witness reported that he heard the airplane's engine "shut off," and stated that it sounded as though the engine was "trying to restart."

Investigators could not determine who was manipulating the flight controls at the time of the accident.

Examination of the airframe and flight controls revealed no mechanical anomalies that would have precluded normal operation.

The engine examination revealed no internal mechanical anomalies that would have precluded normal operation. The left magneto was not located. A teardown of the right magneto revealed that the internal components had been improperly assembled; the distributor gear electrode was not seated properly, and the distributor drive gear was stuck inside the magneto. Given the improper assembly of the right magneto it is likely that the magneto had failed to operate properly, which subsequently resulted in a rough running engine and a partial loss of engine power. It is likely that the flight instructor and student were distracted by the partial loss of engine power, and during the turn toward the open field, lost aircraft control and stalled the airplane, and subsequently hit flat terrain.

Text from the NTSB. Open the NTSB docket for WPR15FA256 for the full record.