Federal Aviation Administration March 9, 2017 – Federal Register Recent Federal Regulation Documents

We are adopting a new airworthiness directive (AD) for all Safran Helicopter Engines, S.A. Arriel 2B turboshaft engines. This AD requires removing any pre-modification (mod) TU 158 hydro-mechanical metering unit (HMU) and replacing with a part eligible for installation. This AD was prompted by a report of an uncommanded in- flight shutdown (IFSD) on a single-engine helicopter, caused by a low returning spring rate of the needle of the HMU. We are issuing this AD to correct the unsafe condition on these products.

We propose to adopt a new airworthiness directive (AD) for all The Boeing Company Model 737-300, -400, and -500 series airplanes. This proposed AD was prompted by a manufacturer's review that showed that the tank access door at a certain wing buttock line did not have an engineered ground path with the mating wing structure. This proposed AD would require replacing the tank access door, doing a check of the electrical bond, doing related investigative and corrective actions if necessary, and revising the maintenance or inspection program by incorporating an airworthiness limitation (AWL). We are proposing this AD to address the unsafe condition on these products.

We propose to adopt a new airworthiness directive (AD) for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes; Model 757 airplanes; and Model 767 airplanes. This proposed AD was prompted by reports of latently failed motor operated valve (MOV) actuators of the fuel shutoff valves. This proposed AD would require replacing certain MOV actuators of the fuel shutoff valves for the left and right engines (all airplanes) and of the auxiliary power unit (APU) fuel shutoff valve (Model 757 and Model 767 airplanes); and revising the maintenance or inspection program, as applicable, to incorporate certain airworthiness limitations (AWLs). We are proposing this AD to address the unsafe condition on these products.