Airworthiness Directive · Amendment 39-22815 · Fuselage
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series airplanes, certificated in any category, as identified in Boeing Alert Requirements Bulletin 777-53A0100 RB, dated March 16, 2023.
The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series airplanes. This AD was prompted by a report indicating multiple findings of cracks in the fuselage skin common to the underwing longeron (UWL). This AD requires external or internal (depending on configuration) inspections for any cracking of the left and right side fuselage skin common to the UWL, and applicable on- condition actions. The FAA is issuing this AD to address the unsafe condition on these products.
Except as specified by paragraph (h) of this AD: At the applicable times specified in the “Compliance” paragraph of Boeing Alert Requirements Bulletin 777-53A0100 RB, dated March 16, 2023, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 777-53A0100 RB, dated March 16, 2023.
Note 1 to paragraph (g): Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin 777-53A0100, dated March 16, 2023, which is referred to in Boeing Alert Requirements Bulletin 777-53A0100 RB, dated March 16, 2023.
Note 2 to paragraph (g): Guidance for accomplishing certain on-condition actions required by paragraph (g) of this AD can be found in Boeing Service Bulletin 777-53-0084, Revision 2, dated December 9, 2020; Boeing Service Bulletin 777-53-0087 Revision 1, dated March 4, 2020; and Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021.
(1) Where the Compliance Time columns of the tables in the “Compliance” paragraph of Boeing Alert Requirements Bulletin 777-53A0100 RB, dated March 16, 2023, use the phrase “the original issue date of Requirements Bulletin 777-53A0100 RB,” this AD requires using the effective date of this AD.
(2) Where Boeing Alert Requirements Bulletin 777-53A0100 RB, dated March 16, 2023, and any service information referenced in Boeing Alert Requirements Bulletin 777-53A0100 RB, dated March 16, 2023, specifies contacting Boeing for repair instructions: This AD requires doing the repair using a method approved in accordance with the procedures specified in paragraph (j) of this AD.
Note 3 to paragraph (h)(2): This note applies to paragraphs (h)(2) and (3) of this AD. Boeing Alert Requirements Bulletin 777-53A0100 RB, dated March 16, 2023, refers to Boeing Service Bulletin 777-53-0084, Revision 2, dated December 9, 2020; Boeing Service Bulletin 777-53-0087, Revision 1, dated March 4, 2020; and Boeing Alert Requirements Bulletin 777-57A0122 RB, dated October 8, 2021.
(3) Where any service information referenced in Boeing Alert Requirements Bulletin 777-53A0100 RB, dated March 16, 2023, specifies applying a cap seal (sealant) to a fastener, fastener head, and fastener threads and collars inside the fuel tank, for this AD, during application of any cap seal to a fastener, fastener head, or fastener threads and collars inside the fuel tank, the cap seal must be applied using a cap sealing procedure with thickness greater than or equal to the dimensions given in Figure 1 to paragraph (h)(3) of this AD.
Note 4 to paragraph (h)(3): Guidance on an acceptable cap sealing procedure for accomplishing the actions required by paragraph (h)(3) of this AD can be found in Boeing Model 777 Aircraft Maintenance Manual (AMM) section 28-11-00.
(4) Where Boeing Alert Requirements Bulletin 777-53A0100 RB, dated March 16, 2023, specifies doing actions “in accordance with Revision 2 of Boeing Service Bulletin 777-53-0084,” for this AD, where flagnote (f) of Figure 7 and Figure 22 of that referenced service information (“Revision 2 of Boeing Service Bulletin 777-53-0084”) includes a sealant callout of Boeing Material Specification (BMS) 5-45 or an optional BMS 5-95, only BMS 5-45 is allowed.
(5) Where Boeing Alert Requirements Bulletin 777-53A0100 RB, dated March 16, 2023, specifies doing actions “in accordance with Revision 1 of Boeing Service Bulletin 777-53-0087,” for this AD, where flagnote (f) of Figure 13 and Figure 49 of that referenced service information (“Revision 1 of Boeing Service Bulletin 777-53-0087”) includes a sealant callout of BMS 5-45 or an optional BMS 5-95, only BMS 5-45 is allowed.
(6) Where Boeing Alert Requirements Bulletin 777-53A0100 RB, dated March 16, 2023, specifies doing actions “in accordance with the original issue of Boeing Alert Requirements Bulletin 777-57A0122 RB,” for this AD, the exceptions specified in paragraph (h)(6)(i) through (v) of this AD apply to that referenced service information (“the original issue of Boeing Alert Requirements Bulletin 777-57A0122 RB”) and the corrections identified in Boeing Multi Operator Message MOM-MOM-24-0054-01B, dated January 26, 2024, apply to that referenced service information.
(i) Where the “Compliance” paragraph of the referenced service information identifies “Tables 1 through 50,” the correct number of tables is Tables 1 through 54.
(ii) The referenced service information does not specify the application of cap seals to underwing longeron fasteners, fastener heads, and fastener threads and collars for the airplane groups and configurations identified in paragraphs (h)(6)(ii)(A) through (D) of this AD. For those airplane groups and configurations, the application of a cap seal to the underwing longeron fasteners at the locations identified in Figures 81 and 144 is required during installation of the underwing longeron and must be applied using a cap sealing procedure with thickness greater than or equal to the dimensions given in Figure 1 to paragraph (h)(3) of this AD.
(A) Groups 7 and 8, Configurations 5 through 8, on the left side.
(B) Group 9, Configurations 1 and 2, on the left side.
(C) Groups 7 and 8, Configurations 2, 6, 10, and 14, on the right side.
(D) Group 9, Configurations 1 and 3, on the right side.
(iii) For any inspection that may require the removal of fastener cap seals, if the cap seal is removed, a cap seal of BMS 5-45 sealant must be reapplied using a cap sealing procedure with a thickness equal to or greater than the dimensions specified in Figure 1 to paragraph (h)(3) of this AD before further flight after completion of the inspection.
(iv) The referenced service information does not require the restoration of any sealant removed to accomplish high frequency eddy current and ultrasonic inspections external to the fuel tank in Figures 1, 7, 11, and 17. Following completion of any inspection required by those figures, replacement of the sealant described in paragraph (h)(6)(iv)(A) and repair of the sealant described in paragraph (h)(6)(iv)(B) of this AD, as applicable, is required.
(A) Where any sealant was removed from the heads of fasteners, before further flight, cover and fillet seal the fasteners using BMS 5-45 or BMS 5-95 sealant.
Note 5 to paragraph (h)(6)(iv)(A): Guidance for accomplishing the actions required by paragraph (h)(6)(iv)(A) of this AD can be found in the Boeing Standard Overhaul Practices Manual (SOPM) section 20-50-19.
(B) Following any sealant replacement required by paragraph (h)(6)(iv)(A) of this AD, where any secondary fuel barrier coating was removed, before further flight, repair the secondary fuel barrier using BMS 5-81 sealant.
Note 6 to paragraph (h)(6)(iv)(B): Guidance for accomplishing the actions required by paragraph (h)(6)(iv)(B) of this AD can be found in Boeing Model 777 Aircraft Maintenance Manual (AMM) section 28-11-00.
(v) The Effectivity of the referenced service information does not include Boeing Model 777F series airplanes having line numbers 1713, 1717, 1720, and 1724 through 1742 inclusive. For those airplanes the applicable actions for Group 6 must be done.
For airplanes on which a front spar lower chord modification specified in Boeing Alert Requirements Bulletin 777-57A0122 RB is done as part of the requirements of paragraphs (g) and (h)(6) of this AD, the modification requirements of paragraph (g) of AD 2023-17-14 are terminated for the applicable side (left or right) on which the modification was done.
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
