What happened
On 13 May 2015, a Piper PA-28-161 Cherokee Warrior II, registration G-HAMR, was conducting a private cross-country flight as part of a group of four aircraft. After departing Oaksey Park, the aircraft arrived at Membury Airfield and joined a right-hand circuit for Runway 05.
Upon touchdown at approximately 70 kt, the pilot attempted to apply the brakes but found them to be unresponsive. Despite increased pressure on the pedals and an attempt by the passenger to assist with the braking, the aircraft failed to decelerate. As the end of the runway approached, the pilot steered the aircraft to the right to avoid the earth bank at the runway's terminus. During this maneuver, the right main landing gear struck concrete blocks positioned to prevent vehicle access from an adjacent road. The impact caused the landing gear to be torn from the aircraft and resulted in significant damage to the propeller, wings, and the underside of the fuselage. The aircraft eventually came to rest against a wire fence. Both occupants exited the aircraft without injury.
The investigation
The investigation examined the mechanical state of the braking system and the physical evidence at the scene. While an insurance representative noted that the hydraulic reservoir was empty, investigators determined this was likely due to the right-hand brake line being severed during the impact with the concrete blocks, as hydraulic fluid was found on a nearby block.
Evidence of skid marks on the ground indicated that the wheels were locked at the moment the aircraft exited the runway, suggesting the brakes were operational. The investigation also considered the runway dimensions, noting that the asphalt strip was only 8 m wide. The aircraft's damage was assessed as being beyond economic repair.
Findings
- The primary cause of the excursion was the impact with concrete blocks which subsequently tore the landing gear from the airframe.
- The pilot's perception of the runway length may have been affected by the narrow 8 m width, potentially causing the end of the runway to approach more rapidly than anticipated.
- The pilot chose to steer toward the right of the runway, avoiding the grass area to the left because parked aircraft were obstructing that space.
- Evidence suggests the braking system was functioning correctly prior to the collision, as indicated by the presence of skid marks.