What happened
During a flight instruction session, a certified flight instructor was providing training to a private pilot/owner in a tail-wheeled airplane. As the aircraft began its takeoff roll on a 5,500-foot-long, 100-foot-wide asphalt runway, it reached nearly takeoff speed before veering to the right.
The instructor attempted to take control of the aircraft to correct the deviation; however, the airplane departed the right side of the runway and underwent a ground loop. During the excursion, the left main landing gear collapsed and the left wing struck the ground. The aircraft eventually came to rest in a grass area approximately 1,132 feet from the start of the runway.
An examination of the runway surface identified a tire mark starting roughly 350 feet from the runway beginning. A second parallel tire mark, located to the left of the first, began at approximately 675 feet from the runway beginning, with both marks continuing to the final position of the aircraft. At the time of the accident, winds were calm.
Findings
Both pilots involved were uncertain if the private pilot had positioned his feet on the rudder pedals in a manner that caused him to inadvertently apply the brakes during the takeoff roll.