What happened
On 30 September 2006, a Piper PA-38-112 Tomahawk, registration G-BGWU, was conducting a private flight at Full Sutton Airfield in Yorkshire. The aircraft completed a standard touchdown on the main wheels of Runway 22. However, once the nosewheel made contact with the runway surface, the aircraft began to veer uncontrollably toward the left.
In an attempt to maintain the centerline, the pilot applied right brake and opposite rudder, but the aircraft continued its leftward trajectory. The aircraft eventually departed the runway and struck a low grass bank that bordered an irrigation pond. The impact caused significant damage to the propeller, fuselage, and left wing, and resulted in the separation of the nosewheel and the left landing gear. There were no injuries to the pilot or the passenger.
The investigation
Investigators examined the wreckage and the aircraft's maintenance records. The inspection of the nosewheel steering mechanism and the torque link confirmed they remained intact following the event. The focus of the investigation centered on the left landing gear attachment bolt, which had failed.
Analysis of the bolt revealed that the fracture surface was composed of two distinct parts: approximately 65% of the surface showed evidence of a fatigue crack progression, while the remaining 35% exhibited characteristics of an overload failure. The investigation also noted that the aircraft's logbook contained no entries regarding any previous heavy landings, making it impossible to establish when the damage to the bolt first occurred.