Accident Narrative
A certificated commercial pilot and one passenger were departing from a 900-foot-long gravel bar in a tail-wheel-equipped airplane operated as an on-demand charter flight. During acceleration, after reaching about 45 knots, the left main landing gear strut fractured above the left wheel axle. The upper portion of the strut dug into the ground, causing the airplane to swerve left. It continued off the left side of the site, and the right wing struck the ground.
Damage
The airplane sustained substantial damage to the right wing and fuselage.
Inspection and Maintenance Background
An operator visual inspection of the fractured strut revealed a fracture through the upper two of four holes drilled in a box pattern near the lower end of the spring steel strut, where the axle is attached outboard. Neither the manufacturer nor the FAA have established a life limit (hours or cycles) for the main landing gear strut. The annual inspection does not require disassembly of the axle from the gear strut, and no inspection procedures other than a general visual inspection of the landing gear have been specified by the manufacturer or the FAA.
Regulatory Response
On March 16, 2001, the NTSB recommended that the FAA issue an airworthiness directive (AD) requiring initial and recurring inspections of Cessna main landing gear spring steel struts using nondestructive inspection techniques. On August 31, 2001, the FAA responded that the current inspection criteria in the Cessna Maintenance Manual are adequate and that additional airworthiness action is not warranted. On March 25, 2002, the NTSB replied that while a visual inspection alone will not detect cracks in the strut, the statistical evidence does not warrant AD issuance at that time. The recommendation was subsequently classified as 'Closed-Reconsidered.'