What happened
On May 4, 2021, a Piper PA-12 Replica, registration TF-XXL, was engaged in a private flight for training purposes at Blönduós Airport. The flight involved the pilot and a passenger, who was also a pilot, performing practice landings on a grass area adjacent to the runway to account for a 15-knot crosswind. The aircraft, which is a homebuilt taildragger equipped with large tires suitable for such terrain, had completed several successful landings prior to the incident.
During the final landing, approximately 100 meters into the landing roll, the pilot was operating the aircraft from the rear seat. While attempting to apply the rudder pedals to maintain directional control, the pilot inadvertently applied the brakes with excessive force. This simultaneous application of the rudder and brakes caused the aircraft to lose stability and overturn.
The investigation
The RNSA examined the configuration of the aircraft's controls, noting that TF-XXL is a homebuilt design capable of being operated from both the front and rear seats. The investigation focused on the pedal arrangement in the rear seat, where the brake pedals are positioned behind the rudder pedals. This layout makes it physically easy to depress both sets of pedals simultaneously if the pilot is not careful.
In contrast, the investigation found that the front seat configuration provides a more offset arrangement, making accidental simultaneous application less likely. The pilot, who had approximately 41.6 hours of experience in this specific aircraft and only about three hours of experience operating it from the rear seat, had been instructed during training to use extreme caution when applying rudder inputs from the rear position.