Special Conditions: Robinson Helicopter Company R66 Helicopters, 14 CFR 27.1309, Installation of an Autopilot (AP) Stabilization Augmentation System (SAS)
This action proposes special conditions for installing an Autopilot Stabilization Augmentation System (AP/SAS) in the Robinson Helicopter Company (Robinson) Model R66 helicopter. This helicopter will have novel or unusual design features associated with installing a complex AP/SAS that has potential failure modes with more severe adverse results than those envisioned by the existing applicable airworthiness standards. The applicable airworthiness standards do not contain adequate or appropriate safety standards for this design feature. This proposed special condition contains the added safety standards the Administrator considers necessary to establish a level of safety equivalent to the existing airworthiness standards.
Airworthiness Directives; Sikorsky Aircraft Corporation Model S-92A Helicopters
This amendment supersedes an existing airworthiness directive (AD) for Sikorsky Aircraft Corporation (Sikorsky) Model S-92A helicopters. That AD currently requires removing all main gearbox (MGB) filter bowl assembly mounting titanium studs (titanium studs) and replacing them with steel studs. This amendment requires the same actions as the existing AD as well as changes to the Rotorcraft Flight Manual (RFM). This amendment is prompted by an accident, by recent RFM changes made by the manufacturer that were not available when we issued the existing AD, and by our determination that certain MGB Normal and Emergency procedures in the RFM are unclear, may cause confusion, and may mislead the crew regarding MGB malfunctions, in particular the urgency to land immediately after warning indications of loss of MGB oil pressure and oil pressure below 5 pounds per square inch (psi).