What happened
On 6 July 2013, a Minicab (JB01 Standard), registration G-AWEP, was performing a private flight from New York Farm in Lincolnshire to a fly-in at Sittles Farm in Lichfield, Staffordshire. The flight began with a takeoff from Runway 26, where the pilot noted a slight left drift during the takeoff roll despite low wind conditions.
Upon arriving at the farm airstrip, the pilot conducted a stable approach at 50 kt and touched down at the start of Runway 27 in a three-point attitude. While the initial rollout was straight, the pilot attempted to apply the heel brakes to slow the aircraft. During this process, the aircraft suddenly yawed to the left. Despite attempts to correct the deviation using right rudder and the right brake, the aircraft veered off the runway at a speed of approximately 10–15 kt. The aircraft entered a field of tall bean crops and subsequently flipped onto its back. There were no injuries to the pilot or the passenger, though the aircraft sustained significant damage to the propeller, cowling, canopy, cabin, and roof.
The investigation
Following the accident, the AAIB examined the aircraft's main landing gear. While the pilot initially suspected the left brake might have been dragging, a physical inspection of the aircraft on jacks revealed a significant mechanical issue. The investigation established that the left wheel could be rotated around the axis of the main landing gear leg by approximately 10–12 degrees.
Upon disassembly of the landing gear assembly, investigators found that the pins connecting the piston to the steel tube had become heavily worn. This wear had caused the holes in the piston to become oval-shaped, allowing for excessive torsional movement. This movement caused the brake cable to pull on the brake even when the pilot was not intentionally applying it.
Findings
- The primary cause of the loss of control was considerable wear in the landing gear component pins, which allowed for excessive rotation of the left wheel.
- This rotation resulted in the uncommanded application of the left cable brake.
- The aircraft veered off the runway into a crop of beans at a low speed, leading to the inversion of the aircraft.