Airworthiness Directive · Amendment 39-21976 · Powerplant
The Boeing Company Airplanes
This AD applies to The Boeing Company airplanes, certificated in any category, as specified in paragraphs (c)(1) and (2) of this AD.
(1) Model 777-200 series airplanes equipped with Pratt & Whitney PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 model turbofan engines.
(2) Model 777-300 series airplanes equipped with Pratt & Whitney PW4090 and PW4098 model turbofan engines.
The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777-200 and -300 series airplanes. This 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 AD). This AD requires 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 issuing this AD to address the unsafe condition on these products.
Before further flight after the effective date of this AD, do the actions specified in paragraphs (g)(1) through (3) of this AD. Repeat the functional check specified in paragraph (g)(3) of this AD within 10 days prior to each flight.
(1) Install debris shields on the T/R inner wall at the left and right sides of the lower bifurcation, in accordance with a method approved by the Manager, Seattle ACO Branch, FAA.
(2) Inspect the fan cowl doors for moisture ingression in accordance with paragraphs (g)(2)(i) or (ii) of this AD, as applicable.
(i) Do the inspection in accordance with a method approved by the Manager, Seattle ACO Branch, FAA. If any moisture ingression is found, repair before further flight, in accordance with a method approved by the Manager, Seattle ACO Branch, FAA.
(ii) Do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 777-71A0092 RB, dated January 13, 2022, except where Boeing Alert Requirements Bulletin 777-71A0092 RB, dated January 13, 2022, specifies to report inspection findings, this AD does not require any report, and where Boeing Alert Requirements Bulletin 777-71A0092 RB, dated January 13, 2022, specifies to contact Boeing for a repair, this AD requires the repair to be accomplished in accordance with a method approved by the Manager, Seattle ACO Branch, FAA.
(3) Do a functional check of the left and right hydraulic pump shutoff valves to ensure they close in response to the corresponding engine fire handle input. If any hydraulic pump shutoff valve does not close, before further flight perform corrective actions until it closes in response to the corresponding engine fire handle input.
Note (1) to paragraph (g)(3): Guidance for accomplishing the actions required by paragraphs (g)(3) and (h)(2) of this AD can be found in the “Engine-Driven Pump (EDP) Shutoff Valve Check” (Subtasks 26-21-00-200-018, 26-21-00-200-019, and 26-21-00-840-022; or Task 29-11-00-710-806) of Boeing 777-200/300 Aircraft Maintenance Manual.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
