Final Report: Gear torque knee failed

 - December 3, 2007, 9:32 AM

Hawker Beechcraft King Air B300, Englewood, Colo., Jan. 8, 2007–The NTSB found that the King Air drifted left on landing and hit a snowbank because the main landing gear upper torque knee failed due to overstress. Investigators also attributed the incident to the pilot’s inability to maintain aircraft control. There were no injuries.
Part of the nosegear upper torque knee was found on the runway at Centennial; the rest remained attached to the gear. Metallurgical examination showed that the lower torque knee was fractured in overstress at two locations: forward and aft of the pivot fastener bore. The aft fracture was consistent with the lower knee being loaded in tension. The forward fracture was deformed more extensively, indicating it was secondary to the aft fracture. There was no evidence of pre-existing cracking, corrosion or damage. According to the manufacturer, early King Airs’ torque knee structure was made of aluminum. Later ones are made of steel. The accident airplane was operated by Shelter Enterprises.