Federal Aviation Administration January 25, 2006 – Federal Register Recent Federal Regulation Documents

The FAA proposes to adopt a new airworthiness directive (AD) for all Mitsubishi Heavy Industries (MHI) MU-2B series airplanes. This proposed AD would require you to do the following: Remove and visually inspect the wing attach barrel nuts, bolts, and retainers for cracks, corrosion, and fractures; replace any cracked, corroded, or fractured parts; inspect reusable barrel nuts and bolts for deformation and irregularities in the threads; replace any deformed or irregular parts; and install new or reusable parts and torque to the correct value. This proposed AD results from a recent safety evaluation that used a data- driven approach to evaluate the design, operation, and maintenance of the MU-2B series airplanes in order to determine their safety and define what steps, if any, are necessary to ensure their safe operation. Part of that evaluation was the identification of unsafe conditions that exist or could develop on the affected type design airplanes. We are issuing this proposed AD to detect and correct cracks, corrosion, fractures, and incorrect torque values in the wing attach barrel nuts, which could result in failure of the wing barrel nuts and/or associated wing attachment hardware. This failure could lead to in-flight separation of the outer wing from the center wing section and result in loss of controlled flight.

The FAA proposes to adopt a new airworthiness directive (AD) for certain Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB- 120, -120ER, -120FC, -120QC, and -120RT airplanes. This proposed AD would require a one-time inspection of the interior of the internal elevator torque tube of each elevator control surface for oxidation and corrosion, and corrective actions. This proposed AD results from corrosion in torque tubes of the elevators found during scheduled maintenance. We are proposing this AD to detect and correct corrosion in the torque tubes of the elevators, which could lead to an unbalanced elevator and result in reduced controllability of the airplane.

The FAA proposes to adopt a new airworthiness directive (AD) for Rolls-Royce Corporation (formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) (RRC) models 250-C30, 250-40, and 250-C47 series turboshaft engines. This proposed AD would add an additional life limit for third- and fourth-stage turbine wheels. This proposed AD results from analysis by RRC of failures of third- and fourth-stage turbine wheels. We are proposing this AD to prevent loss of power, possible engine shutdown, or uncontained failure.

The Federal Aviation Administration (FAA) and the National Park Service (NPS), as co-leads in the environmental process, intend to prepare an Environmental Impact Statement (EIS) under the provisions of the National Environmental Policy Act of 1969, as amended. The EIS will address environmental and related impacts that may result from actions to be proposed and alternatives to be developed to achieve the statutory mandate of Public Law 100-91 (``commonly know as the Overflights Act''); to provide for the substantial restoration of the natural quiet and experience of Grand Canyon National Park (GCNP). The Presidential Memorandum dated April 22, 1996, Earth Day Initiative, Parks for Tomorrow calls for substantial restoration of natural quiet in the GCNP to be achieved by 2008. ``Substantial restoration of natural quiet'' has been defined by the NPS to mean that 50 percent or more of the park will achieve natural quiet (i.e., no aircraft audible) for 75 to 100 percent of the day. This undertaking is a follow-on to previous actions taken by the FAA, in cooperation with the NPS, since December 1996. The FAA and NPS are inviting the public, agencies, and other interested parties to provide comments, suggestions, and input regarding: (1) The scope, issues, and concerns related to the development of proposed and alternative actions at Grand Canyon National Park that provide for the substantial restoration of the natural quiet and experience of the park and protection of public health and safety from significant adverse effects associated with all aircraft overflights; (2) past, present, and reasonably foreseeable future actions which, when considered with any alternatives, may result in significant cumulative impacts; and, (3) potential alternatives. The scoping process for this EIS will include three public meetings and a ninety-day comment period for interested agencies and parties to submit oral and/or written comments representing the concerns and issues they believe should be addressed. Please submit any written comments within ninety-days from the date of this Notice, or no later than April 27, 2006. Address your comments to: Docket Management System, Doc No. FAA-2005-23402, U.S. Department of Transportation, Room Plaza 401, 400 Seventh Street, SW., Washington, DC 20590-0001. The purpose of this Notice is to inform Federal, State, local government agencies, and the public of the intent to prepare an Environmental Impact Statement (EIS) and to conduct a public and agency scoping process. Information, data, opinions, and comments obtained throughout the scoping process will be considered in preparing the Draft EIS. To maximize the opportunities for public participation in this environmental process, the FAA and NPS will also publish notices in the major local newspapers in the vicinity of the study area.