Incident Overview
During ground operations, a student pilot was taxiing the aircraft in preparation for takeoff. The aircraft needed to make a right turn, so the student applied the right brake. However, the aircraft did not respond as expected and failed to turn.
Sequence of Events
The instructor pilot, who was present, assumed control of the aircraft. He first applied the right brake, and when that produced no effect, he applied both brakes simultaneously. The brakes failed to slow or steer the aircraft. By this time, the aircraft was approaching a portable building. Just before impact, the instructor turned off the magneto switches to disable the ignition. The aircraft then struck the portable building.
Post-Incident Examination
Following the incident, the instructor inspected the braking system. He reported that both brakes were worn. Specifically, the left brake was missing a puck, and approximately half of the right brake rotor/disc had separated at its base. The condition of the brakes rendered them ineffective, contributing to the inability to steer or stop the aircraft.