The aircraft was being used for circuit training. During the third touch-and-go landing the left main gear separated from the aircraft. The left wing struck the runway and the aircraft slewed to a halt. Specialist investigation confirmed that one of the main gear retaining bolts was fatigued. Widespread surface corrosion was prsent on the shank of the bolt. The specialist considered that the initial fatigue fractures are corrosion related. Investigation revealed that this type variant is fitted with large wheels and that failure of the gear retaining bolts occurs more frequently with this variant than that fitted with small wheels. The occurrence was not the subject of an on-site examination.
