Cessna 150M N714CW accident near Mount Airy, Maryland

Probable cause

The in-flight fatigue failure of the No. 4 cylinder barrel, which resulted in a total loss of engine power.

NTSB analysis

The private pilot reported that, about 10 minutes after departure, when the airplane was at 2,500 ft mean sea level, the engine was not producing full power. He adjusted his course to be near an airport as a precaution. Shortly after, the engine began to run roughly, then lost more power. The pilot declared an emergency and found a field for landing; during the approach, he adjusted his path to avoid power lines and attempted a downwind approach and landing to the opposite direction. He realized he could not make the field, so he landed on an adjacent field of mature corn. As his airplane touched down, it flipped over, which resulted in substantial damage to the airframe. Postaccident examination of the airplane revealed that the No. 4 cylinder had fractured at the barrel portion of the cylinder, separating from the bottom of the cylinder attach point. Examination of the fracture surfaces revealed a fatigue crack that emanated from a corrosion pit on the outer surface of the barrel portion. The fatigue failure of the No. 4 cylinder barrel led to the loss of engine power.

Text from the NTSB. Open the NTSB docket for ERA15LA368 for the full record.