Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 767-200 and -300 series airplane equipped with Pratt & Whitney Model JT9D or PW4000 engines. This proposed AD was prompted by a report of several cases of low hydraulic pressure or loss of electrical power to the alternating current motor pump (ACMP) on the left engine. This proposed AD would require inspecting for damage of the wiring bundles in the left engine's strut and corrective actions if necessary, and installing new wire support brackets and bundle clamp. We are proposing this AD to detect and correct chafed wire bundles due to rubbing against structure or a hydraulic piping elbow, which could result in electrical arcing in a flammable fluid leakage zone, and would provide a possible ignition source for fuel vapors and hydraulic fluids. Ignited fuel vapors or hydraulic fluid in an area without a fire detection or suppression system could result in an uncontained engine strut fire and structural damage to the engine strut.