A study was completed on CASA aircraft to examine the landing gear structural durability. The gear, designed to a safe life criterion, were approaching their replacement time. Damage tolerance methods were used to extend the life of these components. Critical components were examined, measured, and drawings prepared. A loads analysis using FAA criteria was completed, usage determined through pilot interviews and published data, and a loading spectrum prepared. Additionally, a stress analysis was conducted for each component. Finally, tests were completed to determine inspection intervals. Inspection procedures were determined, and an STC issued by the FAA. As a result, the gear no longer need to be retired when they reach their retirement time. Instead periodic inspections are being used to assess their structural life.