ERA11LA357

According to the pilot, as he taxied the airplane to the runway for takeoff, the left main landing gear collapsed. Examination revealed that the left main landing gear had fractured and completely separated from the airplane about 6 inches outboard of its attachment point at the airframe. Examination of the fracture surface on the section of landing gear leg that remained attached to the airframe revealed features consistent with fatigue failure. Examination of the underside of the landing gear leg in an area directly adjacent to the fatigue zone revealed multiple corrosion pits. The manufacturer's maintenance guidance called for visual inspection of the landing gear every 100 hours, and the maintenance manual included information specific to corrosion control on the landing gear legs.

On June 23, 2011, about 1130 eastern daylight time, a Cessna 182F, N3152U, was substantially damaged after a landing-gear collapse during taxi at Warrenton Airpark (7VG0), Warrenton, Virginia. The certificated airline transport pilot and 4 passengers were not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local skydiving flight, which was conducted under the provisions of 14 Code of Federal Regulations Part 91. According to the pilot, as he taxied the airplane to the runway for takeoff, the left main landing gear collapsed, which resulted in substantial damage to the airplane. Examination revealed the left main landing gear had fractured, and completely separated from the airplane approximately six inches outboard of its attachment point at the airframe. According to Federal Aviation Administration (FAA) records, the pilot, held an airline transport pilot certificate for airplane multiengine land. He also held a commercial pilot certificate for airplane single engine land. In addition, he held a flight instructor certificate, a ground instructor certificate and a flight engineer certificate. His most recent first-class medical certificate application was dated January 28, 2011, but it was denied. He reported 7,200 total hours of flight experience on that date. According to FAA records, an airworthiness certificate was issued for the airplane in 1962. It was a four-seat, high-wing, fixed conventional gear airplane that was equipped with a Continental O-470 engine. The most recent annual inspection was completed November 26, 2010, at 2,679 total aircraft hours. At the time of the accident the airplane accumulated approximately 2,724.6 total flight hours. A National Transportation Safety Board (NTSB) materials specialist subsequently examined the left main landing gear segments in the operator’s hangar. His preliminary examination revealed that the fracture surface on the separated landing gear leg was smeared during the accident sequence. The segment that remained attached to the airframe displayed a “pristine” fracture, which revealed features consistent with fatigue failure. A detailed examination at the NTSB Materials Laboratory, Washington, DC, confirmed the failure due to fatigue. Examination of the underside of the landing gear strut in an area directly adjacent to the fatigue zone, revealed multiple corrosion pits. The Cessna Maintenance Manual (Model 100 Series (1963-68) Section 2 Ground Handling, Servicing, Lubrication and Inspection) included criteria to visually inspect the “Main gear wheels, wheel bearings, step and spring strut, tires, and fairings” every 100 hours. In July 2007, “Section 5 Landing Gear” of the maintenance manual was revised and included information that concerned “Corrosion Control on Landing Gear Springs." Additionally, the Cessna continued airworthiness program included criteria “To inspect main landing gear spring outboard support for corrosion” every 1,000 hours or 3years.