20171128022149I

Aircraft was conducting takeoffs and landings at Reading pa (krdg) for instructional purposes. During landing on runway 18 the right gear oleo cylinder failed to contain the strut/axle assembly resulting in the separation of the landing gear wheel/axle/strut from the aircraft except for the brake hose. The landing gear wheel/axle/strut assembly was trapped between the wing and runway during rollout and supported the wing as the aircraft slid to a stop, remaining on the runway. The student and flight instructor exited the aircraft without assistance and were not injured.

The aircraft came to rest upright and intact on runway heading approximately 1000 feet from the approach end of runway 18. Flight and engine controls are free and correct. Right flap is damaged and right lower wing skin has small punctures and wrinkles from contact with the landing gear wheel. The right oleo strut housing exhibited both torque link mounting ears broken off, several cracks and two broken fragments at the lower end. The broken oleo strut housing has accrued 9752 hours in service. The fractured surfaces of the torque link ears suggest failure initiated at a corrosion pit in the left ear and progressed to overload failure of both ears.

Evidence suggests the torque link ears failed on the previous takeoff allowing the landing gear wheel/axle/strut assembly to hyperextend in the housing and be retained in the housing in flight by the brake hose only. The damage to the strut housing is consistent with the landing gear oleo strut being levered aft while being inserted less that one inch, overloading the end of the housing. The length of the brake hose would have allowed the oleo strut to extend almost completely out of the housing and the subsequent landing would have exerted high lateral force on a small area at the lower end of the strut housing where the seal resides.