Federal Aviation Administration May 4, 2021 – Federal Register Recent Federal Regulation Documents

The FAA is adopting a new airworthiness directive (AD) for certain CFM International, S.A. (CFM) LEAP-1B model turbofan engines. This AD was prompted by multiple reports of pressure sub-system (PSS) unit faults due to pressure transducer corrosion following extended storage periods. For an engine in service, this AD requires checks for engine maintenance messages related to the pressure transducer and, depending on the results of the check, replacement of the PSS unit before further flight. The AD requires this repetitive check for faults prior to each flight until the PSS has accumulated at least 15 hours of electrical power. For an engine not in service, this AD requires applying electrical power to the PSS unit before further flight. The FAA is issuing this AD to address the unsafe condition on these products.

The FAA is superseding Airworthiness Directive (AD) 2019-22- 10, which applied to all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. AD 2019-22-10 required repetitive inspections for cracking of the left- and right-hand side outboard chords of frame fittings and failsafe straps at a certain station around eight fasteners, and repair if any cracking is found. For certain airplanes, this AD reduces the compliance time for the initial inspection, and for all airplanes this AD reduces the repetitive interval. This AD was prompted by a determination that the initial inspection threshold and repetitive inspection interval are inadequate to address the cracking in a timely manner. The FAA is issuing this AD to address the unsafe condition on these products.