Federal Aviation Administration March 16, 2015 – Federal Register Recent Federal Regulation Documents

We are superseding Airworthiness Directive (AD) 2015-02-06 for certain Bombardier, Inc. Model CL-600-2B16 (CL-604 Variant) airplanes. AD 2015-02-06 required a revision to the airplane flight manual, a revision to the maintenance or inspection program, as applicable, and replacement of horizontal stabilizer trim actuators (HSTAs) having certain part numbers. This new AD continues to require those actions and corrects certain typographical errors. This AD was prompted by the discovery of three typographical errors in AD 2015-02-06. We are issuing this AD to detect and correct loose spur gear bolts on the HSTA, which, if combined with the failure of the primary load path, could lead to failure of the HSTA and subsequent loss of the airplane.

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 757-200, -200PF, -200CB, and -300 series airplanes; and Model 767-200, -300, -300F, and -400ER series airplanes. This AD was prompted by reports indicating that the counterweights in some hub assemblies of the ram air turbine (RAT) could be understrength and fracture when the RAT is rotating, and that some RAT hub assemblies were delivered with balance washer retention screws that were incorrectly heat-treated, and therefore, susceptible to fracture and cracking. This AD requires a part number and serial number inspection to determine if certain RAT hub assemblies are installed; and, for affected RAT hub assemblies, doing an inspection for missing and fractured balance washer screws, and replacement or rework if necessary. We are issuing this AD to prevent an inoperative RAT, which, following a dual engine shutdown in flight, will cause loss of all hydraulic power to the primary flight controls, resulting in subsequent loss of control of the airplane.