What happened
On 9 October 2001, a modified Piper L2LS (registration G-BIMM) was conducting a tailwheel type conversion training flight at Clacton Airfield, Essex. The flight involved a student pilot under the supervision of a flying instructor. After completing upper air work, the aircraft proceeded to perform a standard circuit for landing on Runway 18.
According to the instructor, the approach was executed at the appropriate speed with flaps extended. The aircraft touched down smoothly on its main wheels just beyond a footpath located on the runway. Following a brief ground roll, the aircraft began to swing toward the right side of the runway. The pilot attempted to correct the deviation using left rudder, but the control input proved ineffective. The instructor subsequently intervened with left rudder and braking, but the aircraft continued its excursion, exiting the runway through a boundary hedge. The aircraft then encountered an 8-foot drop on the far side of the hedge and came to a halt at the edge of a pond. There were no injuries to the two crew members on board.
The investigation
The investigation examined the aircraft's braking system and the circumstances of the landing. Prior to the flight, the instructor had demonstrated the parking brake operation to the student. During pre-flight checks, the instructor noted that the left brake felt somewhat spongy and that the parking brake did not seem to release clearly. Although the issue did not reappear during taxiing and the left brake appeared to function during the initial takeoff roll, a post-accident engineering inspection was conducted.
Findings
- The left brake was inoperative at the time of the accident.
- A worn 'O' ring in the left caliper had allowed hydraulic fluid to leak around the piston.
- The aircraft's excursion was caused by the loss of directional control resulting from the failure of the left braking component.