What happened
Prior to landing, the pilot calculated the necessary performance requirements for an arrival on a wet runway using the anti-skid system, determining that the available runway length was adequate. The aircraft made a standard touchdown, but during the subsequent deceleration, the aircraft began to oscillate or fishtail. Believing the anti-skid system had malfunctioned, the pilot manually deactivated the system and proceeded with the rollout using conventional braking.
As a result of this action, the aircraft exited the departure end of runway 05. The incident resulted in substantial damage to the aircraft, though no fatalities or injuries were reported.
Findings
An investigation into the event revealed that the aircraft's mechanical systems were fully operational, with no defects found in the anti-skid system. Data regarding landing performance indicated that the runway length was insufficient to safely stop the aircraft on a wet surface without the use of anti-skid assistance. The behavior observed during the braking phase was consistent with dynamic hydroplaning, which caused a total loss of braking efficiency, rather than a mechanical failure of the anti-skid hardware.