This July 2007 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Piper Super Cub.
Location: Talkeetna, Alaska.
Injuries: None.
Aircraft damage: Substantial.
What reportedly happened: The private pilot was landing a tundra tire-equipped airplane on an off-airport grass surface. As he applied the brakes during the landing roll, the left main landing gear collapsed. The airplane pivoted to the left and the left wing hit the ground.
The post-accident inspection revealed that the outboard end of the left main landing gear strut extension was broken through the outer radius of the attaching lug. The airplane was equipped with hydrasorb landing gear shock units, which consist of automotive-type oleo struts, combined with light shock cords. Examination of the landing gear showed extensive corrosion. The landing gear had been installed in 1977, and the most recent annual inspection of the airplane was about one year before the accident.
Probable cause: A fracture and collapse of the main landing gear. Contributing to the accident was an inadequate annual inspection by maintenance personnel and corrosion.