Airworthiness Directives; The Boeing Company Airplanes

We propose to adopt a new airworthiness directive (AD) for all The Boeing Company Model 787-8 and 787-9 airplanes. This proposed AD was prompted by a flight test report indicating that the crew oxygen masks in the flight deck did not deploy correctly. This proposed AD would require an inspection to determine whether any crew oxygen mask having a certain part number is installed at four locations in the flight deck, and replacing affected crew oxygen masks. We are proposing this AD to address the unsafe condition on these products.