Federal Aviation Administration December 5, 2016 – Federal Register Recent Federal Regulation Documents

We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 737-600, -700, -700C, -800, and -900 series airplanes. This proposed AD was prompted by an evaluation by the design approval holder (DAH) indicating that the web lap splices in the aft pressure bulkhead are subject to widespread fatigue damage (WFD). This proposed AD would require repetitive inspections of the web lap splices in the aft pressure bulkhead for cracking of the fastener holes, and repair if necessary. We are proposing this AD to address the unsafe condition on these products.

We are adopting a new airworthiness directive (AD) for all Fokker Services B.V. Model F28 Mark 0070 and 0100 airplanes. This AD was prompted by heavy corrosion found on the wing rear spar lower girder. This AD requires inspections of the affected areas, modification of the wing trailing edge lower skin panels, and corrective actions if necessary. We are issuing this AD to address the unsafe condition on these products.

We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model CL-600-2A12 (CL-601 Variant), and CL-600-2B16 (CL-601-3A, CL-601-3R, and CL-604 Variants) airplanes. This AD was prompted by a report that a potential chafing condition exists between the negative-G fuel feed drain line of the auxiliary power unit (APU) and its surrounding structure and components. This AD requires, for certain airplanes, a detailed inspection for chafing conditions of the negative-G fuel feed drain line of the APU, and corrective actions if necessary. For certain other airplanes, this AD requires replacement of the APU negative-G fuel feed tube assembly and the drain line. We are issuing this AD to address the unsafe condition on these products.