Department of Transportation July 23, 2013 – Federal Register Recent Federal Regulation Documents

The FAA proposes to rule and invites public comment on the release of land at Sioux Gateway Airport/Col. Bud Day Field, Sioux City, Iowa, under the provisions of 49 U.S.C. 47107(h)(2).

We propose to supersede an existing airworthiness directive (AD) for Sikorsky Model S-76A, B, and C helicopters. The existing AD currently requires inspecting the main rotor lower bifilar arm assembly (bifilar arm assembly) for a crack, and if there is a crack, replacing the bifilar arm assembly. The AD also requires a one-time test for the correct torque on the lug nuts, and if necessary, conducting torque stabilization tests. Since we issued that AD, Sikorsky has developed a terminating procedure for the inspections required by the existing AD. This proposed AD would retain the requirements of that AD, and would require replacing the main rotor hub (MRH) pilot with a different part- numbered MRH pilot, which would be terminating action for the requirements of the AD. The proposed actions are intended to prevent failure of a bifilar lug, damage to the main rotor control system, and subsequent loss of control of the helicopter.

We propose to adopt a new airworthiness directive (AD) for Sikorsky Model S-70, S-70A, and S-70C helicopters. This proposed AD would establish a new life limit based on a prorated formula for certain identified components (parts) installed on Model S-70, S-70A, and S-70C helicopters after being previously installed on certain military model helicopters. This proposed AD is prompted by the discovery that certain parts have been interchanged between military helicopter models with different life limits and the possibility that these same parts can be interchanged with civilian models with different life limits. The proposed actions are intended to establish a pro-rated in service life limit for each identified part to prevent fatigue failure of a part and subsequent loss of control of the helicopter.

We are revising an earlier proposed airworthiness directive (AD) for the Sikorsky Model S-70, S-70A, S-70C, S-70C (M), and S-70C (M1) helicopters with General Electric (GE) T700-GE-401C or T700-GE- 701C engines installed, which proposed establishing new fatigue life limits for certain GE engine gas generator turbine (GGT) rotor parts. The proposed AD was prompted by a reevaluation of the method for determining the life limit for certain GE engine gas generator turbine (GGT) rotor parts and the determination that these life limits need to be based on low cycle fatigue (LCF) events instead of hours time-in- service. This action would retain the previously proposed requirements but correct the life limit formula for a certain GGT rotor part. The proposed actions are intended to prevent fatigue failure of a GGT rotor part, engine failure, and subsequent loss of control of the helicopter.

We propose to adopt a new airworthiness directive (AD) for AgustaWestland Model A109S, AW109SP, A119, and AW119 MKII helicopters to require removing certain rod end assemblies from service. This proposed AD is prompted by reports of fractures on the rod end assemblies that could damage the main rotor assembly and lead to loss of control of the helicopter.

The Regulatory Agenda is a semiannual summary of all current and projected rulemakings, reviews of existing regulations, and completed actions of the Department. The intent of the Agenda is to provide the public with information about the Department of Transportation's regulatory activity planned for the next 12 months. It is expected that this information will enable the public to be more aware of and allow it to more effectively participate in the Department's regulatory activity. The public is also invited to submit comments on any aspect of this Agenda.