Ryan Aeronautical ST3KR N59418 accident near Newnan, Georgia

Probable cause

A total loss of engine power for reasons that could not be determined based on the available information.

NTSB analysis

A review of the airplane's maintenance records revealed that the accident flight was the airplane's first flight following an annual inspection. The private pilot and passenger departed on the personal flight and flew about 35 nautical miles to a private airstrip. A witness reported seeing the airplane conduct a low pass over the runway and then enter a climb. As the airplane climbed through about 200 ft above ground level, the engine experienced a sudden loss of power, and the airplane subsequently descended into trees. Video footage from the witness's cell phone corroborated his statement.

Postaccident examination revealed that the engine turned freely by hand when the propeller was rotated, and compression was established on the Nos. 1, 4, and 5 cylinders. No compression was established on the Nos. 2 and 3 cylinders. The No. 3 cylinder was impact-damaged. Examination of the No. 2 cylinder revealed an improperly adjusted intake valve set screw, which prevented the intake valve from closing completely. The No. 2 cylinder set screw was readjusted, and the intake valve subsequently closed normally, and compression was established. However, if the set screw had been set improperly before the flight, the engine problem should have been present throughout the flight rather than developing later in the flight; therefore, the effect of the improperly set screw on the engine performance could not be determined.

Text from the NTSB. Open the NTSB docket for ERA14LA360 for the full record.