Airworthiness Directives; The Boeing Company Airplanes

FAA / Federal Register · 2021-15026

The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 767-300 series airplanes as modified by a certain supplemental type certificate (STC). This AD was prompted by a report that the electrical diagram for the C9066 circuit breaker connection (wiring) for the "Main Deck Oxygen Alert Control" is erroneous and might have resulted in incorrect installation. This AD requires inspecting the wiring connection common to the C9066 circuit breaker and, if necessary, making changes to the wiring connection and testing the main deck oxygen alert system. The FAA is issuing this AD to address the unsafe condition on these products.