Amateur-built SONEX N198PC accident near Crossville, Tennessee

Probable cause

The pilot’s failure to maintain control of the airplane, which resulted in a low-altitude aerodynamic stall/spin. Contributing to the accident was a loss of engine power for reasons that could not be determined during postaccident examination and the pilot’s decision to depart with a known deficiency. Contributing to the pilot’s injuries was his failure to use the installed restraint system.

NTSB analysis

Three days before the accident, a witness heard the airplane’s engine stop while the airplane was taxiing for departure and then restart before the airplane departed uneventfully. On the morning of the accident flight, another witness heard the airplane attempting to depart from the accident airport. During the departure, the engine power reduced suddenly while the airplane was at an altitude of about 15 feet. The airplane then continued to fly at that altitude until reaching the midpoint of the runway, before the engine power again increased, and the airplane began an abrupt climb. Shortly thereafter, another witness reported seeing the airplane in a spin just before it impacted the ground beyond the departure end of the runway.

Postaccident examination of the airplane showed damage signatures consistent with the airplane being in a left-turning aerodynamic stall/spin at impact. Additionally, a witness report, the condition of the cockpit canopy, and the postaccident position of the pilot’s restraints suggested that the pilot was likely not wearing the restraints at impact. Examination of the engine revealed no evidence of any obvious mechanical deficiencies. A definitive determination of the engine’s operational state at impact could not be established based on available evidence; however, the manufacturer of the airplane kit advised pilots to discontinue a takeoff if there were any signs of abnormal engine operation and to investigate the cause before attempting another takeoff.

Text from the NTSB. Open the NTSB docket for ERA13LA024 for the full record.