Cessna 170 N1421D accident near Wheatland, Wyoming

Probable cause

The flight instructor’s incorrect compensation for the gusting crosswind during the landing roll, which resulted in a loss of directional control and runway excursion.

NTSB analysis

The flight instructor in the tailwheel-equipped airplane reported that, during the landing roll, as soon as the tailwheel touched the runway, the airplane veered to the right. He added that he attempted to recover by applying full left rudder, left brake, and right aileron, but the left wing impacted the ground as the airplane exited the runway to the right. Subsequently, the airplane nosed over.

The airplane sustained substantial damage to the right wing lift strut, both wings, and empennage.

The flight instructor reported that skid marks on the runway indicated that the tailwheel was not rolling freely. He added that, during a postaccident inspection, the left brake pedal went to the lower limit on an initial depression, but later held brake pressure during a second depression. He reported that he would not have been able to recover the airplane back to centerline because of the initial brake pressure response.

Further, the flight instructor reported that, about 10 minutes before the accident, the wind was 310° at 13 knots, gusting to 19 knots.

In a followup e-mail, the flight instructor reported that there were no brake or tailwheel anomalies noted during the run-up or departure. He also reported that the student pilot did not make any noticeable control inputs during the landing sequence.

The Federal Aviation Administration inspector reported that, during a postaccident examination of the airplane 2 days after the accident, he "saw nothing abnormal with the brakes," and he added that the tailwheel was turning.

The airplane landed on runway 26. An online commercial weather service provider reported that a nearby station, about 2 minutes before the accident, reported wind 010° at 21 mph, gusting to 24 mph.

The passenger in the rear seat provided a video showing the landing roll from the rear seat looking forward. Both the right and left control yokes can be seen, but the rudder pedals cannot be seen. During the beginning of the sequence, the instructor, in the right seat, had his right hand on the control yoke, and the student, in the left seat, had his left hand on the control yoke. Right aileron was applied. During the landing roll, the student added his right hand to the control yoke, and as the airplane veered to the right, left aileron was applied. The camera panned to the left as the right wing lifted and the left wing impacted the ground. The airplane veered left, then nosed over.

Text from the NTSB. Open the NTSB docket for GAA17CA141 for the full record.