Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 777-200, 777-200LR, 777-300, 777- 300ER, and 777F series airplanes. This proposed AD was prompted by reports of wing anti-ice (WAI) valve failure that can result in undetected structural damage to leading edge (LE) slat assemblies, and separately a failure of the autothrottle (A/T) to disconnect after advancing the throttle levers, which caused a low speed condition during a go-around. This proposed AD was also prompted by a determination that insufficient low-speed protection exists in the 777 fleet and a determination that the flightcrew may not recognize and properly respond to a multi-channel unreliable airspeed event. This proposed AD would require installing certain new software, and doing a software configuration check. The FAA is proposing this AD to address the unsafe conditions on these products.