What happened
On 23 June 2018, a Vans RV-8, registration G-JBTR, was performing a private flight when it departed the runway at Perth Airport. The aircraft touched down on the asphalt runway in an almost three-point attitude, facing a light 5 kt crosswind from the right. While the aircraft initially maintained a straight track with all three wheels in contact with the surface, a sudden rightward turn occurred two to three seconds after touchdown.
Despite the pilot's efforts to use the rudder and wheelbrakes to correct the direction, the aircraft veered off the paved surface. As the aircraft slid sideways at a groundspeed of roughly 40 kt, the left main landing gear collapsed. This impact caused the propeller and the left wing to strike the ground, resulting in extensive damage to the airframe. The two occupants were able to exit the aircraft without injury.
The investigation
Investigators examined the wreckage and the circumstances surrounding the loss of directional control. The investigation found no evidence of mechanical defects contributing to the incident. The pilot noted that a tyre squeal preceded the sharp turn to the right. The pilot also considered the possibility that an inadvertent application of the right brake may have initiated the turn, potentially causing the left mainwheel to lift. This sequence would have rendered subsequent left-brake applications ineffective and reduced rudder authority as the aircraft's speed decreased.