Czech Sport Aircraft As PIPER SPORT N957MD accident near Peachtree City, Georgia

Probable cause

The pilot's incomplete assessment of the risk presented by operating an airplane with an unresolved history of engine power losses; a partial loss of engine power during takeoff due to operation of the engine with an excessively rich fuel/air mixture; and the pilot's subsequent exceedance of the airplane's critical angle of attack, which resulted in an aerodynamic stall and impact with trees.

NTSB analysis

**This report was modified on March 17, 2021. Please see the public docket for this accident to view the original report.**

The private pilot, who was aware that the light sport airplane's engine had not been functioning normally, took off to fly to another airport where an engine-specific mechanic was located. Downloaded avionics data indicated that, during the airplane's initial climb after takeoff, engine rpm decreased about 14%. Beyond the end of the runway, about 50 ft above ground level, the airplane's pitch attitude increased to about 19°, while roll increased to about 28°. The airplane exceeded its critical angle of attack and entered an aerodynamic stall, impacting the ground in a nose-low attitude. Due to his injuries, the pilot could not recall the accident sequence of events or his actions after takeoff.

Subsequent examination of the engine revealed that the spark plugs were mostly black in color and some were encrusted with debris. It is likely that, during the takeoff, a fouled spark plug did not provide adequate voltage to the firing tip, and a cylinder did not fire properly. Fouled spark plugs are consistent with a very rich fuel mixture; however, the reason for the rich mixture could not be determined.

Text from the NTSB. Open the NTSB docket for ERA14LA316 for the full record.