Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 777 airplanes. This proposed AD would require installing software upgrades to the airplane information management system (AIMS) located in the flight compartment. This proposed AD results from an investigation that revealed that detrimental effects could occur on certain AIMS software during flight. We are proposing this AD to prevent an unannunciated loss of cabin pressure. If an undetected loss of pressure event were to cause an unsafe pressure in the cabin, the flight crew could become incapacitated.