Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to adopt a new airworthiness directive (AD) for certain Model 767-200, -300, and -300F series airplanes. This proposed AD would require inspecting to verify the part number of the low- pressure flex-hoses of the flightcrew and supernumerary oxygen system installed under the oxygen mask stowage box at a flightcrew and supernumerary oxygen mask location, and replacing the flex-hose with a new non-conductive low-pressure flex-hose if necessary. This proposed AD results from reports of a low-pressure flex-hose of the flightcrew oxygen system that burned through due to inadvertent electrical current from a short circuit in an adjacent audio select panel. We are proposing this AD to prevent inadvertent electrical current, which can cause the low-pressure flex-hoses used in the flightcrew and supernumerary oxygen systems to melt or burn, resulting in oxygen system leakage and smoke or fire.