Piper PA-28-180 N9179J accident near Oxford, Iowa

Probable cause

The failure of the pilot receiving instruction to recover from the practice stall before the airplane entered a spin and the flight instructor's inadequate monitoring of the pilot receiving instruction and delayed remedial action to recover the airplane.

NTSB analysis

The private pilot had not flown in several years and was receiving instruction from a flight instructor. Radar data indicated that the pilots were performing ground reference maneuvers during the flight. The data showed that the airplane maintained an altitude of 3,400 ft mean sea level, about 2,600 ft above ground level, before it made a left turn and entered a rapid descent. A witness reported that he heard the engine popping and backfiring, and it appeared as if the airplane wasn't moving forward. According to the witness, the nose of the airplane then dropped, and the airplane entered a spiral and completed eight or nine rotations, before it entered a straight nose-down dive that continued to impact A postaccident examination of the airframe and engine did not reveal any anomalies consistent with a preimpact failure or malfunction. It is likely that the private pilot was practicing a stall from which he did not recover before the airplane entered a spin. In addition, had the instructor been appropriately monitoring the private pilot's actions he would have been able to provide remedial action to recover from the stall/spin.

Text from the NTSB. Open the NTSB docket for CEN17FA147 for the full record.