Department of Transportation April 17, 2006 – Federal Register Recent Federal Regulation Documents

This action withdraws a notice of proposed rulemaking (NPRM). That NPRM proposed to revise the existing airworthiness directive (AD) applicable to Rolls-Royce plc (RR) Model RB211 Trent 892, 884, 877, 875, and 892B series turbofan engines. That proposed rule would have required initial and repetitive inspections of the angled drive upper shroud, the intermediate gearbox housing (IGH), and the external gearbox lower bevel box (LBB) housing, and initial and repetitive master magnetic chip detector (MCD) inspections. Since we issued that proposed rule, RR notified us that after reviewing the service experience and the original actions taken, the unsafe condition no longer exists and mandatory actions required by the proposed rule are no longer required. Accordingly, we withdraw the proposed rule.

The FAA proposes to revise an existing airworthiness directive (AD) for certain Turbomeca Arriel 1B, 1D, 1D1, and 1S1 turboshaft engines. That AD currently requires initial and repetitive position checks of the gas generator 2nd stage turbine blades on all Turbomeca Arriel 1B, 1D, 1D1, and 1S1 turboshaft engines. That AD also currently requires initial and repetitive replacements of 2nd stage turbines on 1B, 1D, and 1D1 engines only. This proposed AD revision would require the same actions, but would relax the compliance times for initially replacing 2nd stage turbines in Arriel 1B, 1D, and 1D1 turboshaft engines. This proposed AD revision results from a request by Turbomeca to clarify the compliance times for 2nd stage turbine initial replacement on Arriel 1D, 1D1, and 1B turboshaft engines. We are proposing this AD revision to clarify and relax the AD compliance times for 2nd stage turbine initial replacement on Arriel 1B, 1D, and 1D1 turboshaft engines. We are also proposing this AD revision to prevent inflight engine shutdown and subsequent forced autorotation landing or accident.

The Federal Aviation Administration (FAA) announces its determination that the revised noise exposure maps submitted by the Maryland Aviation Administration for Baltimore/Washington International Thurgood Marshall Airport under the provisions of Title I of the Aviation Safety and Noise Abatement Act of 1979 (Pub. L. 96-193) and CFR part 150 are in compliance with applicable requirements.

This action establishes Class D airspace at Bay St. Louis, MS. A Federal contract tower with a weather reporting system is being constructed at the Stennis International Airport. Therefore, the airport will meet the criteria for establishment of Class D airspace. Class D surface area airspace is required when the control tower is open to contain existing Standard Instrument Approach Procedures (SIAPs) and other Instrument Flight Rules (IFR) operations at the airport. This action will establish Class D airspace extending upward from the surface, to and including 2,500 feet MSL, within a 4.2-mile radius of the airport.

This document publishes in the Federal Register an amendment adopting emergency airworthiness directive (EAD) 2006-06-51 that we sent previously to all known U.S. owners and operators of GEAE CT7-8A turboshaft engines installed on Sikorsky S92 helicopters. This AD requires initial and repetitive inspections of the electrical chip detectors for the No. 3 bearing. This AD results from two failures of the No. 3 bearing in GEAE CT7-8A engines. We are issuing this AD to prevent failures of the No. 3 bearings and possible dual in-flight shutdowns of the engines.

This amendment amends Standard Instrument Approach Procedures (SIAPs) for operations at certain airports. These regulatory actions are needed because of changes occurring in the National Airspace System, such as the commissioning of new navigational facilities, addition of new obstacles, or changes in air traffic requirements. These changes are designed to provide safe and efficient use of the navigable airspace and to promote safe flight operations under instrument flight rules at the affected airports.

This amendment adopts a new airworthiness directive (AD) for the specified Brantly International, Inc. (Brantly) model helicopters. This action requires certain inspections and measurements of the upper tail rotor vertical gearbox (gearbox), vertical shaft (shaft) and shaft housing (housing) and their associated parts; and of the intermediate gear box bushing (bushing). This amendment is prompted by an accident and an incident report of fatigue cracking of a shaft. The actions specified in this AD are intended to prevent fatigue cracking of a shaft, failure of a shaft, and subsequent loss of control of the helicopter.