What happened
The incident occurred during a dual primary cross-country flight involving a student pilot and a certified flight instructor. The aircraft was conducting an approach and landing sequence at Prescott. According to the flight instructor's account, the initial phase of the approach and the touchdown on the runway surface appeared normal. However, as the airspeed decreased, the aircraft began to drift toward the right side, initiating a gradual turn.
The student pilot attempted to apply control inputs to correct this deviation and maintain the runway centerline. These corrections proved unsuccessful. Consequently, the aircraft continued its uncontrolled turn and ground looped off the right side of the runway, coming to rest in the soft soil adjacent to the pavement.
The investigation
A subsequent examination of the aircraft by a repair station identified a critical mechanical failure responsible for the loss of directional control. The tail wheel steering pawl was found to be broken. This defect prevented proper steering functionality; specifically, the mechanism would only allow the aircraft to steer to the right and failed to engage entirely for leftward steering inputs.
Review of the flight instructor's logbook revealed that he had accumulated approximately 150 hours of experience in the certified flight instructor role. Additionally, records indicated that the student pilot's entire flight time was accrued in Cessna 120 and 180 model aircraft.
Findings
The flight instructor acknowledged that he likely waited too long to take control of the aircraft from the student pilot. He described the student as an excellent performer, suggesting that the loss of control was primarily due to the mechanical failure rather than pilot error alone. The broken tail wheel steering pawl rendered the aircraft unable to correct the rightward drift effectively.