Federal Aviation Administration May 17, 2018 – Federal Register Recent Federal Regulation Documents

We are superseding Airworthiness Directive (AD) 2018-09-10 for all CFM International S.A. (CFM) Model CFM56-7B engines. AD 2018-09-10 required initial and repetitive inspections of the concave and convex sides of the fan blade dovetail to detect cracking and replacement of any blades found cracked. This AD requires the same initial and repetitive inspections but revises the compliance time for the initial inspections of certain higher-risk fan blades. This AD was prompted by a recent engine failure due to a fractured fan blade that resulted in the engine inlet cowl disintegrating and debris penetrating the fuselage, causing a loss of pressurization, and prompting an emergency descent. We are issuing this AD to address the unsafe condition on these products.

This notice contains a summary of a petition seeking relief from specified requirements of Federal Aviation Regulations. The purpose of this notice is to improve the public's awareness of, and participation in, the FAA's exemption process. Neither publication of this notice nor the inclusion or omission of information in the summary is intended to affect the legal status of the petition or its final disposition.

We propose to adopt a new airworthiness directive (AD) for Airbus Helicopters Model AS355E, AS355F, AS355F1, AS355F2, and AS355N helicopters. This proposed AD would require measuring a vibration level in the tail rotor (T/R) drive. This proposed AD is prompted by reports of bearing degradation. The actions of this proposed AD are intended to prevent an unsafe condition on these helicopters.

This action proposes to remove Class D airspace, Class E airspace designated as a surface area, and Class E airspace designated as an extension to a Class D and Class E airspace at Henry Post Army Air Field (AAF), Fort Sill, OK; amend Class D airspace and Class E airspace designated as a surface area at Lawton-Fort Sill Regional Airport, Lawton, OK; and amend Class E airspace extending upward from 700 feet above the surface at Lawton-Fort Sill Regional Airport and Henry Post AAF. The FAA is proposing this action due to the closure of the air traffic control tower (ATCT) at Henry Post AAF. The name of Lawton-Fort Sill Regional Airport and the geographic coordinates of Henry Post AAF would also be updated to coincide with the FAA's aeronautical database, and the outdated term ``Airport/Facility Directory'' would be replaced with the term ``Chart Supplement.''

This action amends Class D airspace, and Class E surface area airspace at Greenwood-Leflore Airport, Greenwood, MS, by making an editorial change to the legal descriptions replacing ``Airport-Facility Directory'' with the term ``Chart Supplement''. This action also removes the part-time Notice to Airmen (NOTAM) language from Class E airspace designated as an extension to Class D airspace. Controlled airspace is necessary for the safety and management of instrument flight rules (IFR) operations at the airport. This action also updates the geographic coordinates of the airport in the Class designations noted in this proposal to coincide with the FAA's aeronautical database. Also, this action corrects the geographic coordinates published in the proposal incorrectly.