Ercoupe 415 N3538H accident near Centre Hall, Pennsylvania

Probable cause

The partial loss of engine power due to the No. 2 cylinder exhaust valve being stuck.

NTSB analysis

The private pilot reported that, after takeoff, he climbed the airplane to 200 ft above ground level, at which point it experienced an "appreciable" loss of engine power, the flight controls became "sluggish," and the airplane would no longer climb. He noted that the engine was operating about 275 rpm below the nominal full-power setting of 2,275 rpm at takeoff. The pilot chose to conduct a forced landing to a field directly off the departure end of the runway. During the landing roll, the airplane struck fences, which resulted in substantial damage to both wings.

Postaccident examination of the engine revealed that the No. 2 cylinder exhaust valve was stuck in the open (compressed) position without rocker-arm contact. The valve remained in the open position through several rotations of the crankshaft. The stuck exhaust valve would have resulted in the partial loss of engine power and the airplane's inability to climb.

Text from the NTSB. Open the NTSB docket for ERA18LA007 for the full record.