What happened
On 3 March 2003, a Europa aircraft, registration G-BVLH, was performing a private flight from Brunton Airfield in Northumberland. The weather conditions were excellent, with calm winds and clear visibility. As the pilot applied power for takeoff on Runway 2le, the aircraft accelerated smoothly along the dry, well-maintained surface.
As the aircraft reached an airspeed of 40 KIAS and became light on its main landing gear, it suddenly veered to the left. The pilot was unable to correct the deviation, causing the aircraft to exit the left side of the runway. The left wing struck a wire fence running parallel to the runway, causing the aircraft to spin left and then continue backwards and to the right through the fence. The impact resulted in the aircraft breaking into two pieces. The pilot was able to shut off the fuel and exit the aircraft safely without injury.
The investigation
Following the accident, an investigation was conducted involving an examination of the rudder cables and a metallurgical analysis of the components. While the pilot found most controls to be serviceable, the rudder cables showed significant damage. The right cable had failed entirely at the cable shortener, while the left cable had suffered a partial failure in the same area.
Metallurgical testing of the cables, the operating arm, and the shorteners revealed that the strand failures were caused by tensile failure due to mechanical overload. This overload occurred specifically at points where the cables were in contact with the shorteners. While the cables themselves met the manufacturer's minimum strength requirements, testing demonstrated that the presence of these specific shorteners reduced the effective strength of the cables by approximately 20%.
Findings
- The primary cause of the loss of directional control was the failure of the rudder cables.
- The cable shorteners used on the aircraft featured sharp plate edges that the cables passed over, which significantly compromised the cables' structural integrity.
- The manufacturer's recommended design for shorteners uses bolts to guide the cable, avoiding the sharp edges found on the proprietary parts used in this accident.