Airworthiness Directives; The Boeing Company Airplanes

FAA / Federal Register · 2021-27838

The FAA proposes to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 777-200 and -300 series airplanes. This proposed AD was prompted by reports of three incidents involving in-flight fan blade failures on certain Pratt & Whitney engines ("fan blades" are also known as "1st-stage low-pressure compressor (LPC) blades"--these terms are used interchangeably in this proposed AD). This proposed AD would require installation of debris shields on the thrust reverser (T/R) inner wall at the left and right sides of the lower bifurcation, inspection of the fan cowl doors for moisture ingression, repetitive functional checks of the hydraulic pump shutoff valves to ensure they close in response to the fire handle input, and corrective actions if necessary. The FAA is proposing this AD to address the unsafe condition on these products.