What happened
On 26 May 2013, a Slingsby T67A Firefly, registration G-BIOW, was performing a private flight departing from Sherburn in Elmet Airfield in North Yorkshire. During the takeoff roll on Runway 29, the pilot experienced a minor vibration felt through the rudder pedals at the moment of rotation. Following this sensation, a decision was made to divert the aircraft to Humberside Airport. After completing a practice approach, the pilot shut down the engine, fuel, and battery before performing a landing on the foam-covered runway at Humberside. The aircraft remained upright during the landing, and both the pilot and the passenger escaped without injury. The incident resulted in damage to the propeller and the nose landing gear.
The investigation
Investigators examined the nose landing gear assembly to determine the cause of the mechanical failure. The investigation established that the upper portion of the torque link had failed, causing the lower part of the link to detach from the aircraft. This detachment left the link still attached to the lower oleo assembly. Maintenance records and inspections revealed that a circlip, which was intended to secure the oleo into the gear leg, had become detached. This failure allowed the oleo assembly to drop out of the leg as the aircraft became airborne.