Incident Overview
A student pilot was landing when a left drift developed, which then evolved into a ground loop. During the ground loop, the aircraft's tailwheel impacted a drainage ditch and muddy terrain located off the left side of the runway.
Flight History
On previous flights, the certified flight instructor (CFI) had occupied the left seat because the airplane was not equipped with brake pedals for the right seat. However, due to the student pilot's demonstrated competency, the CFI chose to occupy the right seat during the accident flight.
Aircraft Configuration
The airplane lacked brake pedals for the right seat, which had previously necessitated the instructor's presence in the left seat. The CFI's decision to sit in the right seat on the accident flight was based on the student's demonstrated proficiency.