The pilot was conducting superphosphate spreading operations from a short narrow agricultural strip. During the landing roll on the trip prior to the accident the pilot felt something unusual about the landing gear so he inspected the wheels but found nothing abnormal. The oleos and torque links were not inspected. During the subsequent take off the left mainwheel and oleo strut separated from the landing gear assembly fracturing the hydraulic brake line. The pilot flew the aircraft to his base aerodrome and carried out a landing on the grass strip without further damage. An inspection of the landing gear showed that the left main torque link attachment bolt had failed allowing the oleo and wheel to separate from the landing gear assembly. The bolt was not recovered therefore the precise reason for the failure of the bolt was not determined. The investigation revealed that this is a recurring problem with this aircraft type due to shear load fatigue of the attachment bolt.
