Airworthiness Directive · Amendment 39-18062 · Nacelles/pylons
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 777-200 and -300 series airplanes, certificated in any category; equipped with Pratt and Whitney engines; as identified in Boeing Service Bulletin 777-54A0024, Revision 2, dated January 23, 2014.
We are superseding Airworthiness Directive (AD) 2011-09-11, for certain The Boeing Company Model 777-200 and -300 series airplanes. AD 2011-09-11 required repetitive inspections for hydraulic fluid contamination of the interior of the strut disconnect assembly; repetitive inspections for discrepancies of the interior of the strut disconnect assembly, if necessary; repetitive inspections of the exterior of the strut disconnect assembly for cracks, if necessary; corrective action if necessary; and an optional terminating action for the inspections. This new AD adds, for certain airplanes, an inspection of the side and top cover plates to determine if all cover plate attach fasteners have been installed, and installing any missing fasteners including doing an inspection for damage, and repair if necessary. This AD was prompted by reports of side and top cover plates installed with missing fastener bolts, which results in an unsealed opening on the system disconnect assembly. We are issuing this AD to detect and correct hydraulic fluid contamination, which can cause cracking of titanium parts in the system disconnect assembly; and also to detect and correct missing fasteners, which results in unsealed openings on the system disconnect assembly. Both unsafe conditions can compromise the engine firewall and result in fire hazards for both the engine compartment and the strut.
This paragraph restates the requirements of paragraph (g) of AD 2011-09-11, Amendment 39-16673 (76 FR 24354, May 2, 2011), with revised service information. Within 12 months after June 6, 2011 (the effective date of AD 2011-09-11): Do a general visual inspection for hydraulic fluid contamination of the interior of the strut disconnect assembly, in accordance with Part 1 of the Accomplishment Instructions of Boeing Service Bulletin 777-54A0024, Revision 1, dated November 4, 2010; or Revision 2, dated January 23, 2014. As of the effective date of this AD, use only Boeing Service Bulletin 777-54A0024, Revision 2, dated January 23, 2014, for accomplishing the actions in this paragraph.
(1) For airplanes on which no hydraulic fluid contamination is found (Condition 1): Repeat the general visual inspection required by paragraph (g) of this AD thereafter at intervals not to exceed 6,000 flight cycles or 750 days, whichever occurs first.
(2) For airplanes on which hydraulic fluid contamination is found (Condition 2): Before further flight, do a detailed inspection for discrepancies (e.g., hydraulic fluid coking, heat discoloration, cracks, and etching or pitting) of the interior of the strut disconnect assembly, in accordance with Part 2 of the Accomplishment Instructions of Boeing Service Bulletin 777-54A0024, Revision 1, dated November 4, 2010; or Revision 2, dated January 23, 2014. As of the effective date of this AD, use only Boeing Service Bulletin 777-54A0024, Revision 2, dated January 23, 2014, for accomplishing the actions in this paragraph.
(i) For airplanes on which no discrepancy is found during the inspection required by paragraph (g)(2) of this AD (Condition 2A): Repeat the detailed inspection required by paragraph (g)(2) of this AD thereafter at intervals not to exceed 6,000 flight cycles or 750 days, whichever occurs first.
(ii) For airplanes on which hydraulic fluid coking or heat discoloration is found but no cracking, etching, or pitting is found during the inspection required by paragraph (g)(2) of this AD (Condition 2B): Do the actions required by paragraph (g)(2)(ii)(A) and (g)(2)(ii)(B) of this AD.
(A) Within 300 flight cycles after doing the inspection required by paragraph (g)(2) of this AD: Do a detailed inspection of the exterior of the strut disconnect assembly for cracks, in accordance with Part 3 of the Accomplishment Instructions of Boeing Service Bulletin 777-54A0024, Revision 1, dated November 4, 2010; or Revision 2, dated January 23, 2014; and repeat the detailed inspection thereafter at intervals not to exceed 300 flight cycles. As of the effective date of this AD, use only Boeing Service Bulletin 777-54A0024, Revision 2, dated January 23, 2014, for accomplishing the actions in this paragraph.
(B) Within 6,000 flight cycles or 750 days after hydraulic fluid coking and/or heat discoloration was found during the inspection required by paragraph (g)(2) of this AD, whichever occurs first: Replace the titanium system disconnect assembly with an Inconel system, in accordance with Part 4 of the Accomplishment Instructions of Boeing Service Bulletin 777-54A0024, Revision 1, dated November 4, 2010; or Revision 2, dated January 23, 2014. As of the effective date of this AD, use only Boeing Service Bulletin 777-54A0024, Revision 2, dated January 23, 2014, for accomplishing the actions in this paragraph.
This paragraph restates the requirements of paragraph (h) of AD 2011-09-11, Amendment 39-16673 (76 FR 24354, May 2, 2011), with revised service information. For airplanes on which any crack, etching, or pitting is found during any inspection required by paragraph (g)(2) or (g)(2)(ii)(A) of this AD (Condition 3): Before further flight, replace the titanium system disconnect assembly with an Inconel system, in accordance with Part 4 of the Accomplishment Instructions of Boeing Service Bulletin 777-54A0024, Revision 1, dated November 4, 2010; or Revision 2, dated January 23, 2014. As of the effective date of this AD, use only Boeing Service Bulletin 777-54A0024, Revision 2, dated January 23, 2014, for accomplishing the actions in this paragraph.
This paragraph restates the requirements of paragraph (i) of AD 2011-09-11, Amendment 39-16673 (76 FR 24354, May 2, 2011), with revised service information. Replacing the titanium system disconnect assembly with an Inconel system disconnect assembly in accordance with Part 4 of the Accomplishment Instructions of Boeing Service Bulletin 777-54A0024, Revision 1, dated November 4, 2010; or Revision 2, dated January 23, 2014; terminates the actions required by paragraphs (g) and (h) of this AD. As of the effective date of this AD, use only Boeing Service Bulletin 777-54A0024, Revision 2, dated January 23, 2014, for accomplishing the actions in this paragraph.
For airplanes on which the system disconnect assembly has been replaced in accordance with Part 4 of the Accomplishment Instructions of Boeing Service Bulletin 777-54A0024, dated April 1, 2010; or Revision 1, dated November 4, 2010: Within 1,125 days after the effective date of this AD, do a detailed inspection of the cover plate fasteners to determine if all cover plate attach fasteners are installed, in accordance with Part 5 of the Accomplishment Instructions of Boeing Service Bulletin 777-54A0024, Revision 2, dated January 23, 2014. If any fastener is missing, before further flight, install fasteners (including doing a detailed inspection for damage of the electrical components and repairing any damaged components), in accordance with Part 6 of the Accomplishment Instructions of Boeing Service Bulletin 777-54A0024, Revision 2, dated January 23, 2014.
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
