Summary
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to all of the airplanes identified above. The existing AD currently requires revising the FAA-approved maintenance program to include a new airplane maintenance manual task that specifies a detailed inspection after each ram air turbine (RAT) retraction. That existing AD also currently requires, for certain airplanes, a one-time inspection to detect breaks in the bottom flange fitting of the RAT and corrective actions, if necessary; for certain airplanes, an adjustment of the ejection jack; and, for certain other airplanes, replacement of the aluminum part with an improved steel part. This proposed AD also would continue to require certain actions for additional airplanes and would revise the FAA-approved maintenance program to include procedures for replacing the RAT swivel coupling fork fitting with a new steel part only. This proposed AD results from a report that an additional swivel coupling of the RAT yoke fitting was found cracked while accomplishing the requirements of the existing AD. We are proposing this AD to prevent misrigging of the ejection jack of the RAT and to ensure removal of any RAT yoke fitting made from aluminum material. Such conditions could result in a broken or cracked swivel coupling and consequent failure of the RAT yoke fitting, which could result in the loss of RAT function and possible loss of critical flight control systems in the event of certain emergency situations.