Summary
The FAA is revising an earlier proposed airworthiness directive (AD) for all Gulfstream Model GV and certain Model GV-SP series airplanes. The original NPRM would have required a one-time inspection of the left and right aileron and elevator actuators to determine the part and serial numbers of each actuator, repetitive inspections of suspect actuators to detect broken damper shafts, and replacement of any actuator having a broken damper shaft. The original NPRM would also have required that operators report any broken damper shaft they find to the FAA. The original NPRM would also have provided an optional terminating action for the repetitive inspection requirements of the proposed AD. The original NPRM resulted from reports of broken or cracked damper shafts within the aileron and elevator actuator assemblies. This action revises the original NPRM by proposing to mandate the previously optional terminating action. We are proposing this supplemental NPRM to prevent broken damper shafts, which could result in locking of an aileron or elevator actuator (hard-over condition), which would activate the hard-over protection system (HOPS), resulting in increased pilot workload and consequent reduced controllability of the airplane.