Federal Aviation Administration March 18, 2016 – Federal Register Recent Federal Regulation Documents

We propose to adopt a new airworthiness directive (AD) for certain BRP-Powertrain GmbH & Co KG Rotax 912 F2, 912 F3, 912 F4, 912 S2, 912 S3, 912 S4, 914 F2, 914 F3, and 914 F4 reciprocating engines. This proposed AD was prompted by a design change introduced by the manufacturer that relocated the engine cylinder head temperature sensor to a different location and converted it to a coolant temperature sensor. This proposed AD would require re-identification of the engine model and concurrent modification of the aircraft to indicate the maximum coolant temperature limit. We are proposing this AD to prevent exceeding engine coolant temperature limits, which could result in loss of engine coolant, damage to the engine, and loss of control of the airplane.

This action proposes special conditions for the Cirrus Design Corporation (Cirrus), model SF50 airplane. This airplane will have a novel or unusual design feature(s) associated with a whole airplane parachute recovery system. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777 airplanes. This AD was prompted by reports of fire and smoke at the engine aft pylon area resulting from fuel leakage caused by a damaged O-ring in the fuel coupling attached to the wing front spar. This AD requires applying sealant to fill the gap between the lower wing panels adjacent to the strut aft vapor barrier. We are issuing this AD to prevent fire and smoke at the engine aft pylon area in the event of a fuel leak, which could cause personal injury during ground operations. A fire spreading back and up to the aft fairing pylon can result in an uncontrolled fire in the strut and ignite the fuel tank.

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-300, -400, and -500 series airplanes. This AD was prompted by reports of cracking at certain fastener locations in the window corners of the window belt area. This AD requires repetitive high frequency eddy current (HFEC) inspections for fatigue cracking in certain fastener locations in the window corners of the window belt area, and related investigative and corrective actions if necessary. This AD also provides an optional preventive modification that terminates the inspections at the modified location. We are issuing this AD to detect and correct fatigue cracking around fastener locations that could cause multiple window corner skin cracks, which could result in rapid decompression and loss of structural integrity of the airplane.

We are superseding Airworthiness Directive (AD) 2012-15-13, for certain The Boeing Company Model 747-100B SUD, 747-300, 747-400, and 747-400D series airplanes; and Model 747-200B series airplanes having a stretched upper deck. AD 2012-15-13 required inspections for cracking and discrepancies of certain fasteners; modification of the frame-to-tension-tie joints; repetitive post-modification inspections; related investigative and corrective actions if necessary; and repetitive inspections for cracking in the tension tie channels, and repair if necessary. For certain airplanes, AD 2012-15-13 also required an inspection to determine if the angle is installed correctly, and re- installation if necessary; and an inspection at the fastener locations where the tension tie previously attached to the frame prior to certain modifications, and repair if necessary. This new AD adds a new inspection for cracking in the tension tie channels and post- modification inspections of the modified tension ties for cracking, and repair if necessary. This AD was prompted by an evaluation indicated that the upper deck is subject to widespread fatigue damage (WFD). We are issuing this AD to prevent fatigue cracking of the tension ties, shear webs, and frames of the upper deck, which could result in rapid decompression and reduced structural integrity of the airplane.