Summary
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to all Short Brothers Model SD3-60 and SD3- SHERPA airplanes. The existing AD currently requires an inspection of the fork end of the rear pintle pin on each main landing gear (MLG) to verify that sealant is properly applied and is undamaged, and related investigative/corrective actions if necessary. This proposed AD would add an inspection for correctly applied sealant on the MLG rear pintle pin assemblies, and related investigative/corrective actions if necessary. This proposed AD would also expand the applicability of the existing AD. This proposed AD results from a new report of a cracked pintle pin fork end. We are proposing this AD to prevent stress- corrosion cracking and subsequent failure of the MLG.