Cessna 172 N1827Y accident near Cedar Key, Florida

Probable cause

A partial loss of engine power due to a stuck exhaust valve and the noncertificated pilot's inadequate preflight planning, which resulted in the airplane being overloaded, both of which led to the airplane's inability to attain a positive climb rate. Contributing to the accident was the pilot's improper decision to attempt to return to the airport at low altitude and his subsequent failure to maintain adequate airspeed and his exceedance of the airplane's critical angle of attack, which led to an aerodynamic stall.

NTSB analysis

Two witnesses reported that, during the first takeoff attempt, the accident airplane's engine was "sputtering," and the pilot aborted the takeoff about halfway down the 2,355-ft-long runway. The noncertificated pilot reported that, during the accident takeoff, the airplane would not climb out of ground effect. (The witnesses stated that the engine sounded normal.) When the airplane reached about 100 ft above ground level, the pilot attempted to return to the airport; however, the airplane descended and impacted shallow water about 600 ft short of the runway. Postaccident examination of the airplane revealed damage consistent with a

Review of weight and balance data and loading information revealed that the airplane's gross weight at the time of the accident was about 50 lbs over its maximum allowable gross weight and that the center of gravity was at or beyond the forward limit. The pilot's loading of the airplane placed it outside of its operating envelope, which likely significantly degraded its performance.

Postaccident examination of the engine found one exhaust valve stuck in the "open" position. If the valve had been stuck during all or a portion of either takeoff, the airplane's acceleration and climb performance would have been significantly degraded.

It is likely that the airplane was unable to attain a positive climb rate due to a combination of the stuck exhaust valve and the pilot's operation of the airplane over its weight limit. It is also likely that, while attempting to return to the airport instead of landing straight ahead, the pilot failed to maintain adequate airspeed and exceeded the airplane's critical angle of attack, which led to an aerodynamic stall.

Text from the NTSB. Open the NTSB docket for ERA17LA024 for the full record.