N333DG

On June 14, 2002, about 2359 Alaska daylight time, a wheel-equipped Cessna 185F airplane, N333DG, sustained substantial damage when the right wing struck the ground following a main landing gear strut failure during takeoff from an off airport site located about 30 miles northwest of Talkeetna, Alaska. The airplane was being operated as a visual flight rules (VFR) on-demand charter flight under Title 14, CFR Part 135, when the accident occurred. The certificated commercial pilot, and the one passenger, were not injured. Visual meteorological conditions prevailed, and a company flight plan was in effect.

During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge on June 15, the pilot reported that during acceleration for takeoff from a 900 foot long gravel bar, after reaching about 45 knots, the left main landing gear strut fractured above the left wheel axle. The upper portion of the gear strut dug into the ground, and the airplane swerved to the left. The airplane continued off the left side of the site, and the right wing struck the ground. The airplane sustained substantial damage to the right wing and fuselage.

The lower end of the spring steel landing gear strut has four holes drilled through the metal in a box pattern. The axle assembly, utilized when wheels and tires are installed, is attached to the outboard side of the strut.

The operator reported that a visual inspection of the fractured landing gear strut revealed a fracture through the upper two holes in the gear strut. At the time of the accident, the airplane had accumulated about 6,042 hours in service. The time in service of the failed gear strut is unknown.

Currently, neither the manufacturer (Cessna Aircraft), nor the Federal Aviation Administration (FAA), have established a life limit (hours or cycles) for the main landing gear strut. An annual inspection does not require disassembly of the axle from the gear strut. The manufacturer, or the FAA, has specified no inspection procedures, other than a general visual inspection of the landing gear.

On March 16, 2001, in a letter addressed to the FAA's administrator in Washington D.C., the NTSB recommended that the FAA issue an airworthiness directive (AD) to require an initial and recurring inspections of Cessna main landing gear spring steel struts, using nondestructive inspection techniques. On August 31, 2001, the FAA reported to the NTSB that the current visual inspection criteria outlined in the Cessna Maintenance Manual are adequate to detect cracks in the main landing gear struts, and that additional airworthiness action is not warranted. On March 25, 2002, the NTSB responded by stating, in part: "The Safety Board continues to believe that a visual inspection alone will not detect cracks in the Cessna main landing gear spring struts. However, the Safety Board acknowledges that the statistical evidence does not warrant issuance of ADs at this time as called for in the Board's recommendation." The safety recommendation was then classified as: "Closed-Reconsidered."