Beech G58 N669CS accident near Taylorville, Illinois

Probable cause

The flight instructor’s failure to verify that the left engine was operational, which resulted in insufficient engine power being available during an attempted go-around and his subsequent loss of airplane control. Contributing to the accident was the instructor's inadequate monitoring of the approach, which led to his failure to notice that the airplane was lined up with a taxiway and necessitated the go-around.

NTSB analysis

The pilot receiving instruction and the flight instructor were conducting an instructional flight to help prepare the pilot for the multiengine practical examination. The pilot stated that, while returning to the base airport and about 7,500 ft above ground level (agl), the instructor reduced power on the left engine to simulate a single engine-out emergency. The student then identified, verified, and feathered the left engine propeller.

About 7,000 ft agl, the instructor advised the pilot that they were going to conduct a simulated dual engine-out emergency and reduced the right engine power to idle. About 3 miles from the airport, the instructor advised that he was going to restart the feathered left engine, and the left propeller began turning, which led him to believe the engine was operating; however, he did not verify that the engine was operating. The instructor advised the pilot to conduct a straight-in approach and target 1,000 ft down the runway. As the airplane neared the airport with full flaps and the landing gear lowered for landing, the instructor realized that it was lined up with a taxiway. The instructor pushed the throttles forward, took the control yoke, and instructed the pilot to "get the wheels up for a go-around." Subsequently, the airplane entered a steep left turn and then impacted a cornfield adjacent to the airport. The instructor's inadequate monitoring of the approach led to his failure to see that the airplane was lined up with a taxiway instead of a runway, which necessitated the go-around.

Data downloaded from the airplane's onboard avionics showed that, about 4.5 minutes before the accident, the left engine fuel flow and rpm decreased to zero, consistent with the engine being shut down and feathered. The rpm and fuel flow remained at zero for about 4 minutes and then began to increase. Subsequently, the fuel flow began to drop below minimum fuel flow levels again, and the rpm remained about 2,000 and decreased as the airspeed decreased, which is indicative of the instructor's failure to restart the engine. It is likely that the instructor saw the propeller windmilling and assumed it was rotating under power.

The Federal Aviation Administration noted in a General Aviation Joint Steering Committee Safety Enhancement Topic bulletin that "single-engine go-arounds in light twin [airplanes] often don't go well and they should be avoided if possible." Because the instructor did not recognize that the airplane only had one engine operating, there was insufficient power for a go-around, which resulted in the instructor's subsequent loss of airplane control.

Text from the NTSB. Open the NTSB docket for CEN15LA280 for the full record.