What happened
On the morning of the incident, the pilot performed a maintenance test flight following an extended period of the aircraft being in maintenance. The flight included the pilot, a pilot-rated passenger, and one other individual. After departing and remaining within the traffic pattern, the aircraft proceeded with an approach and landing.
During the landing roll, the Cessna pulled sharply to the left. The pilot brought the aircraft to a stop on the runway and notified the control tower that the occupants were safe but that the aircraft was experiencing a braking problem. Upon exiting the aircraft, an occupant observed that the left main landing gear torque links had separated and the main landing gear tire had rotated.
An occupant noted that the approach appeared slightly short due to an approaching storm, while the passenger reported that the flight was high and fast with full flaps extended. The passenger also noted that the landing was harder than usual and that the pilot remarked the aircraft pulled to the left as if a brake had locked up. The passenger assisted in maintaining directional control until the aircraft came to rest. No injuries were reported.
The investigation
Following the incident, the aircraft was raised on jacks, and the torque links were reconnected before being towed to the ramp. An inspection of the left main landing gear wheel assembly revealed that the assembly had rotated 15 to 20 degrees from its normal position. The upper and lower link assemblies (p/n 5141005-7 and 5141005-9) were disconnected, though the securing bolt, bushing, two AN washers, castellated nut, cotter pin, and hydraulic hose clamp remained installed in the upper link assembly.
A subsequent examination of one of the incident washers by the NTSB revealed an outside diameter of approximately .570 inch and a thickness of approximately .061 inch. The required washer (P/N 5045018-1) has an outside diameter of .750 inch and a thickness of .032 inch. A Cessna Service Kit dated November 23, 1983, specifies the installation of a -2 washer under the bolt head and nut that secure the torque links.
Records indicated the aircraft had undergone an annual inspection on May 16, 2003. Discrepancy sheets from that inspection showed that both main landing gears had been removed and reinstalled from another aircraft, specifically N402DD. At the time of the incident, the aircraft had flown only 0.25 hours since the completion of the annual inspection.