Airworthiness Directives; The Boeing Company Airplanes

FAA / Federal Register · 2020-06092

The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 787-8, 787-9, and 787-10 airplanes. This AD requires repetitive cycling of the airplane electrical power. This AD was prompted by a report that the stale-data monitoring function of the common core system (CCS) may be lost when continuously powered on for 51 days. This could lead to undetected or unannunciated loss of common data network (CDN) message age validation, combined with a CDN switch failure. The FAA is issuing this AD to address the unsafe condition on these products.