On May 22, 2003, about 1128 eastern daylight time, a Cessna 402C, N402DD, registered to and operated by Langston Air Charters LLC, experienced separation of the upper and lower torque link assemblies of the left main landing gear while landing at the Kendall-Tamiami Executive Airport, Miami, Florida. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 CFR Part 91 local maintenance test flight. The airplane was not damaged and there were no injuries to the airline transport rated pilot, pilot-rated passenger in the copilot's seat, or rear seat passenger. The flight originated about 5 minutes earlier from the Kendall-Tamiami Executive Airport. The pilot reported that on the morning of the incident he was asked by the owner of the airplane to perform a maintenance test flight due to the airplane being in maintenance for "a month." He along with the pilot-rated right front seat occupant, and another individual performed a complete preflight inspection of the airplane. The flight departed, and remained in the traffic pattern. The approach and landing were normal until during the landing roll, when the airplane pulled sharply to the left. He brought the airplane to a stop on the runway and advised the control tower that he and the occupants were safe and they had a braking problem. One of the occupants who is the president of the facility that had just completed the annual inspection exited the airplane and noted that the left main landing gear torque links were separated and the main landing gear tire was rotated. The airplane was raised on jacks, the torque links were reconnected, and the airplane was towed to the ramp. The president of the facility that had just completed the annual inspection of the airplane who was on-board at the time of the incident reported that to him, the approach appeared to be a little "...short, but it looked ok, due to the storm that was coming in fast he wanted to land before it closed the airport in." The right front seat occupant commented several times that the flight was high and fast. Full flaps were extended, and the airplane was landed "...a bit hard to what I'm used to, the pilot said simultaneously when landing that 'the aircraft was pulling to the left like if the brake had locked up.'" The right front seat occupant helped to maintain directional control of the airplane until it came to rest. He got out of the airplane and noted the left main landing gear wheel assembly was rotated 15-20 degrees to the left from the normally installed position, and the upper and lower link assemblies (p/n 5141005-7 and 5141005-9, respectively), were not connected to each other. Additionally, the upper and lower link assemblies securing bolt, bushing, two AN washers, castellated nut, cotter pin, and clamp securing the flexible hydraulic hose remained installed in the upper link assembly. He further stated that following recovery of the airplane, a hard landing inspection of the landing gear was performed and no damage was noted. The airplane was towed to the ramp where the landing gear was repaired before NTSB and FAA could examine the airplane. NTSB examination of one of the incident washers revealed the outside diameter measured approximately .570 inch, and the thickness was approximately .061 inch. The specified part number (P/N) for the washer for the incident airplane is 5045018-1 (-1), or when exhausted used P/N 5045018-2 (-2). The specified outside diameter for the -1 and -2 washers is .750 inch, while the inside diameter specification is .313 inch + .031 inch. The -1 washer is .032 inch thick while the -2 washer is .063 inch thick. Cessna Service Kit SK 421-118 (Service Kit), dated November 23, 1983, calls for the replacement of washers under the bolt and nut, and for inspection of the torque links. The Service Kit specifies washer P/N 504518-2 to be installed under the bolt head and nut, with replacement washer P/N S1450-5H12-063 which will be incorporated into the next revision to the Service Kit. The airplane was last inspected on May 16, 2003, in accordance with an annual inspection using 14 CFR Part 43 appendix D, and the "Inspection Time Limits" specified in the airplane maintenance manual. Review of the "Inspection Time Limits" guide related to the main landing gear revealed the torque links are inspected for condition and security, then serviced. Review of the discrepancy sheets for the last annual inspection revealed both main landing gears were removed and installed into another airplane, with the corrective action reading, "reinstalled right and left main landing gear on N402DD." According to the hour meter, the airplane had been operated for .25 hour at the time of the incident since the annual inspection was completed. At the time of the incident, Safe Air International, Inc., dba Island Express Airlines was leasing the airplane from the registered owner. The Director of Operations (D.O.) for Island Express reported that the incident pilot did not have permission to operate the airplane, and he was not an employee of Safe Air International, Inc. The D.O. also reported that Island Express did not authorize the test flight and they were first made aware of the test flight after the incident had occurred. The owner of the airplane reported that 2 days before the incident, a certified letter was sent on his behalf by an attorney to Island Express advising that the owner had taken possession of the incident airplane and the lease was "...in default." The airplane minus the retained AN175-20 bolt, AN310-5 nut, and washer was released to Ken Langston, manager of Langston Air Charters LLC, on June 7, 2004. The retained parts were also released to Mr. Langston, on June 8, 2004.