History of the Flight
On 30 September 2006 at 1800 UTC, a Piper PA-38-112 Tomahawk (registration G-BGWU) was landing on Runway 22 at Full Sutton Airfield, Yorkshire. The pilot, aged 61, held a National Private Pilot's Licence and had 167 hours total flying experience, with 71 hours on type. After a reportedly normal touchdown on the main wheels, the aircraft veered to the left when the nosewheel contacted the ground. Despite the pilot applying opposite rudder and right brake, the aircraft continued turning left, departed the runway, and traversed the corner of a small grass bank surrounding an irrigation pond. The impact with the bank resulted in the separation of the nose and left landing gear, damage to the propeller, left wing, and fuselage. The aircraft came to rest on a taxiway at the holding point for Runway 22. Both the pilot and passenger were uninjured.
Aircraft Examination
An inspection of the aircraft after the incident revealed that the nosewheel steering mechanism and torque link were intact. However, the left landing gear main attachment bolt had failed. Examination of the bolt showed it had failed in a region where the bolt had been deformed. Approximately 65% of the fracture surface exhibited evidence of crack progression due to a fatigue mechanism, with the remaining 35% showing characteristics of an overload failure. Discolouration of the fatigue fracture surface indicated that the crack had been present in the bolt for some time before it failed.
Bolt Deformation and Fatigue
The most probable cause of the deformation was considered to have been a heavy landing, which may also have been the initiating event for the fatigue crack. The aircraft logbook contained no record of such an event, so it was not possible to determine how long the damage had been present prior to the accident.