What happened
On 27 April 2000, a Beech 58, registration N80HC, was performing a private flight at Southampton Airport. While taxiing for takeoff, the pilot had back-tracked along the runway and intended to turn onto the 'dumb-bell' area at the runway end to align with Runway 20. To facilitate a wide right-hand turn, the pilot applied slight left braking. However, upon attempting to apply the right brake to complete the maneuver, the aircraft failed to respond.
Because the aircraft was traveling at a speed too low for rudder effectiveness, it drifted toward the edge of the tarmac. As the aircraft approached the grassed area, the pilot shut down both engines. Despite the shutdown, the left propeller remained in motion as the left main wheel sank into the soft ground, causing the propeller to strike the edge of the tarmac. The aircraft became stuck in the soft earth and required extraction via air bags before being towed to a maintenance hangar.
There were no injuries to the pilot during the incident, though the aircraft sustained damage to the left main landing gear door and the left propeller was bent due to engine shock loading.
The investigation
Investigators reviewed the accident report submitted by the pilot and examined records from the maintenance organization. Testing conducted by the maintenance team revealed that the right landing wheel would not brake when the right brake pedal was operated from either pilot's position. Interestingly, braking action was only achieved if the left and right pedals were pressed simultaneously.
Findings
- The investigation established that a defective right brake shuttle valve was the primary cause of the loss of directional control.
- Although a physical inspection of the dismantled valve showed no visible wear or damage, replacing the component restored full braking functionality to the aircraft.