What happened
On 21 November 2017, a Christen Eagle II, registration G-KLAW, was performing a private flight when it experienced a loss of directional control during the landing phase at RNAS Yeovilton. As the aircraft decelerated below 40 knots, the pilot attempted to use differential braking to maintain the runway centerline against a crosswind originating from the right. However, the left brake pedal lost pressure and moved to the floor, providing almost no braking force on that side. Consequently, the aircraft veered right, rotating through 200° before coming to a halt. There were no injuries to the pilot or the passenger on board.
The investigation
The investigation focused on the mechanical state of the braking system following the excursion. A detailed strip-down inspection of the braking unit was conducted. This examination revealed that one of the brake calipers had been leaking for an extended period. This leak likely resulted in the loss of braking pressure observed by the pilot during the landing roll.
Findings
- The primary cause of the excursion was the inability to apply effective differential braking due to a mechanical failure.
- A leak in one of the brake calipers had been present for some time prior to the accident.
- The presence of a crosswind from the right side of the runway exacerbated the loss of directional control once the braking asymmetry occurred.
- The aircraft sustained damage to the tailwheel, the main landing gear, and the fabric on the lower left wing.