Incident Summary
An aircraft experienced a brake failure after landing on a gravel bar on the Robertson River. The pilot intentionally executed a ground loop to avoid striking a ditch, but during the maneuver the tail wheel impacted the ditch, causing the fuselage to buckle.
Sequence of Events
Upon touchdown on the gravel bar, the left wheel's brake 'went soft.' The pilot allowed the airplane to continue its landing roll. As the aircraft approached a ditch, the pilot intentionally initiated a ground loop to prevent the airplane from striking the ditch. During the ground loop, the tail wheel struck the ditch, and the force of the impact caused the fuselage to buckle.
Examination Findings
Post-incident examination of the aircraft revealed that the left brake's torque plate had sheared, which resulted in a broken brake line. The torque plate failure likely led to the loss of brake pressure described by the pilot as the brake 'going soft.'