Federal Aviation Administration February 7, 2013 – Federal Register Recent Federal Regulation Documents

The FAA proposes to rule and invite public comment on the request for permanent easement at the Dallas/Fort Worth International Airport under the provisions of Section 125 of the Wendell H. Ford Aviation Investment Reform Act for the 21st Century (AIR 21).

We propose to supersede an existing airworthiness directive (AD) that applies to all Turbomeca S.A. Arrius Models 2B, 2B1, and 2F turboshaft engines. The existing AD currently requires replacement of injector manifolds and borescope-inspection of the flame tube and the high-pressure (HP) turbine area for possible damage. Since we issued that AD, we received a report that the corrective actions of the existing AD were insufficient to eliminate the unsafe condition. This proposed AD would require, depending on the engine model, repetitive replacements of fuel injection manifolds and the privilege injector, or, repetitive replacements of the privilege injector. We are proposing this AD to prevent an uncommanded in-flight shutdown of Arrius 2B1 and 2F turboshaft engines and damage to the helicopter.

We propose to adopt a new airworthiness directive (AD) for certain Engine Alliance GP7270 and GP7277 turbofan engines. This proposed AD was prompted by damage to the high-pressure compressor (HPC) stage 7-9 spool caused by failure of the baffle plate feature on affected HPC stage 6 disks. This proposed AD would require initial and repetitive borescope inspections of the baffle plate feature and removal from service of the HPC stage 6 disk before further flight, if the plate is missing material. This proposed AD would also require mandatory removal from service of these HPC stage 6 disks at the next HPC module exposure. We are proposing this AD to prevent uncontained failure of the HPC stage 7-9 spool, uncontained engine failure, and damage to the airplane.

We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 747-400 series airplanes. This proposed AD was prompted by reports of auxiliary power unit (APU) faults due to power feeder cable chafing. This proposed AD would require detailed inspections for damage of the APU power feeder cables; replacing the clamps and installing grommets; and related investigative and corrective actions if necessary. We are proposing this AD to detect and correct chafing of the APU power feeder cables within a flammable fluid leakage zone, which, with arcing, could result in fire and structural damage.