Incident Details
Following takeoff, the pilot selected the landing gear up but the corresponding position light did not illuminate. The landing gear motor circuit breaker was found tripped. During subsequent attempts, the pilot was unable to fully extend or retract the landing gear. The destination airport control tower verified during a fly-by that the landing gear was not fully extended after the pilot had attempted an emergency landing gear extension. The pilot then retracted the landing gear as much as possible and performed a wheels-up landing on a grass area adjacent to a runway. The airplane sustained substantial damage to a fuselage bulkhead during the landing.
Landing Gear Examination
Inspection of the airplane showed that the right main landing gear was partially extended, with its wheel and lower strut assembly rotated within the wheelwell. The bolt that attached the upper and lower portions of the torque link assembly was sheared in half. The lower torque link was jammed against the wheelwell structure, which restricted the movement of the entire landing gear assembly.
Bolt Failure Analysis
The bolt fracture features were consistent with shear overstress, as a result of torsion during the action of the torque link assembly. The bolt fracture face did not contain any evidence of fatigue cracking. The separated bolt sections were seized within the upper and lower torque links, as a result of surface corrosion.