Sequence of Events
The student pilot, on a solo navigation exercise, was returning to Land's End Airfield. The wind was light south-westerly at about five knots, visibility greater than 10 km, and cloud base at 2,200 ft amsl. Runway 25, a grass runway 695 m in length with a displaced threshold reducing landing distance to 630 m, was in use.
Following a stable approach at 80 to 85 mph with full flap selected, the aircraft made a smooth landing, touching down further along the damp grass runway than normal. With idle power selected, the pilot allowed the aircraft to slow to about 40 mph before applying the hand-operated brakes. The aircraft veered rapidly to the left through approximately 30º. The pilot released the brakes and tried to regain directional control but found that no amount of pressure on the right rudder pedal would turn the aircraft back to the right. As the aircraft headed towards a boundary hedge, the pilot reapplied the brakes, causing the aircraft to veer further to the left as it slowed. The pilot estimated the aircraft struck the hedge at about 25 mph and then stopped.
Aftermath
The pilot, uninjured, vacated G-ASPK without delay through the cockpit door. Although a smell of fuel was present, there was no fire. The aircraft sustained damage to the spinner, nose landing gear, engine cowling, wings, and windscreen.
Witness Observations
Two witnesses considered that the aircraft had landed longer than usual; one thought the combination of the long landing and speed would result in a go-around. The authorising instructor commented that once the aircraft had veered through 30º or more, it would have been very difficult to regain the original heading, especially on a damp grass surface.
Pilot's Comments and Brake Examination
The pilot was unable to explain why the aircraft had veered left after brake application or why he could not correct the turn. He considered it possible that uneven braking due to damp surface conditions or that he had been pushing against a part of the aircraft structure other than the right rudder pedal. He estimated the braking action as medium/good. An initial examination of the brakes confirmed that, when progressively applied, they operated correctly and acted evenly on both main wheels. A photograph taken after the accident of the aircraft's tracks across the grass surface revealed a steady, continuous turn to the left.