Federal Aviation Administration February 21, 2017 – Federal Register Recent Federal Regulation Documents

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 757 airplanes. This AD was prompted by reports of single and multiple uncommanded spoiler panel extensions during flight when there was a hydraulic system failure. This AD requires replacing certain spoiler power control units (PCUs) with new or changed PCUs. We are issuing this AD to address the unsafe condition on these products.

We are superseding Airworthiness Directive (AD) 2011-10-17 for all Airbus Model A300 and A310 series airplanes, and Model A300 B4-600, B4-600R, and F4-600R series airplanes, and Model C4-605R Variant F airplanes (collectively called A300-600 series airplanes). AD 2011-10- 17 required revising the maintenance program by incorporating certain airworthiness limitation items (ALIs). This AD requires revising the maintenance or inspection program, as applicable, to incorporate new or revised structural inspection requirements. This AD also removes Model A310 and A300-600 series airplanes from the applicability. This AD was prompted by a revision of certain ALI documents, which specify more restrictive instructions and/or airworthiness limitations. We are issuing this AD to address the unsafe condition on these products.

We are superseding Airworthiness Directive (AD) 2012-16-07 for certain The Boeing Company Model 737-500 series airplanes. AD 2012-16- 07 required inspections of the fuselage skin at the chem-milled steps, and repair if necessary. This new AD adds new inspections, permanent repairs of time-limited repairs, related investigative and corrective actions if necessary, and skin panel replacement. This AD was prompted by evaluation by the design approval holder (DAH) that indicates that the fuselage skin is subject to widespread fatigue damage (WFD), and reports of cracking in certain areas of the fuselage skin. We are issuing this AD to address the unsafe condition on these products.