Incident Summary
A private pilot reported that during landing on a paved runway, the airplane, equipped with tail wheel and tundra tires, experienced a hard touchdown. Subsequently, the left main landing gear assembly collapsed, and the left wing struck the runway, resulting in structural damage.
Investigation Findings
An inspection of the main landing gear (MLG) assembly was conducted by the National Transportation Safety Board (NTSB) investigator-in-charge and Federal Aviation Administration (FAA) certification engineers. The examination revealed that the MLG was not an approved component, despite being stamped with "PMA" (Primary Manufacturing Authority), which typically indicates an approved part. Further analysis determined that the gear had fractured at the shock strut attachment lugs, and these lugs were approximately half the strength of the original factory equipment.
The MLG assembly involved in the incident has been available for several years and can be retrofitted to the entire Piper Cub series of airplanes.
Regulatory Actions
The FAA aircraft certification branch, in coordination with the manufacturer, is currently reviewing the design of the MLG assembly. The manufacturer has indicated that a Service Bulletin will be published, offering a strengthened version of the MLG. Additionally, the FAA will issue either a Special Airworthiness Information Bulletin (SAIB) or an Airworthiness Directive (AD) to address the issue.