Airworthiness Directive · Amendment 39-18016 · Fuselage
the Boeing Company Airplanes
This AD applies to The Boeing Company Model 747-100, 747-100B, 747-200B, 747-200C, 747-200F, 747-400F, 747SR, and 747SP series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010.
We are superseding Airworthiness Directive (AD) 2012-13-08 for certain the Boeing Company Model 747-100, 747-100B, 747-200B, 747-200C, 747-200F, 747-400F, 747SR, and 747SP series airplanes, without a stretched upper deck or stretched upper deck modification. AD 2012-13- 08 required inspections of tension ties and surrounding structure for cracking, and related investigative and corrective actions if necessary; modification of tension tie structure or tension tie and frame structure at specified stations; and post-modification inspections of some modified and unmodified areas, and repair if necessary. This new AD adds inspections in unmodified center section tension ties, and repair if necessary; post-modification inspections of modified and unmodified areas, and repair if necessary; a new modification of tension tie and frame structures; and inspections of tension ties and surrounding structure, and related investigative and corrective actions if necessary. This new AD reduces an inspection interval. This AD was prompted by widespread fatigue damage analysis that resulted in a determination that more inspections are necessary. We are issuing this AD to prevent tension ties from becoming severed or disconnected from the frames, which could lead to reduced structural integrity and sudden decompression of the airplane in flight.
This paragraph restates the requirements of paragraph (g) of AD 2012-13-08, Amendment 39-17110 (77 FR 40481, July 10, 2012). For Group 1, and Groups 3 through 6 airplanes identified in Boeing Special Attention Service Bulletin 747-53-2502, dated April 21, 2005: At the applicable time in paragraph (g)(1) or (g)(2) of this AD, do detailed and high frequency eddy current (HFEC) inspections for cracking of each affected tension tie and of the surrounding structure. If any cracking is found: Before further flight, do all applicable corrective and related investigative actions. Do all actions in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 747-53-2502, dated April 21, 2005; or Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010. Where Boeing Special Attention Service Bulletin 747-53-2502, dated April 21, 2005; or Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010; specifies to contact Boeing for repair instructions: Before further flight, repair the area using a method approved in accordance with the procedures specified in paragraph (n) of this AD. As of August 14, 2012 (the effective date of AD 2012-13-08), only Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010, may be used to accomplish the actions required in this paragraph.
(1) For airplanes identified in Boeing Special Attention Service Bulletin 747-53-2502, dated April 21, 2005, as Groups 1, 3, and 6 airplanes: Do the first inspections before the accumulation of 20,000 total flight cycles, or within 1,000 flight cycles after February 16, 2006 (the effective date of AD 2006-01-07, Amendment 39-14446 (71 FR 1947, January 12, 2006)), whichever occurs later; and repeat the inspections thereafter at intervals not to exceed 4,000 flight cycles until the modification required by paragraph (j) of this AD is accomplished.
(2) For airplanes identified in Boeing Special Attention Service Bulletin 747-53-2502, dated April 21, 2005, as Groups 4 and 5 airplanes: Do the first inspections before the accumulation of 17,000 total flight cycles, or within 1,000 flight cycles after February 16, 2006 (the effective date of AD 2006-01-07, Amendment 39-14446 (71 FR 1947, January 12, 2006)), whichever occurs later; and repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles until the modification required by paragraph (j) of this AD is accomplished.
This paragraph restates the requirements of paragraph (h) of AD 2012-13-08, Amendment 39-17110 (77 FR 40481, July 10, 2012). For Group 2 airplanes identified in Boeing Alert Service Bulletin 747 53A2502, Revision 1, dated June 17, 2010: At the applicable times specified in paragraphs (h)(1) and (h)(2) of this AD, do detailed and HFEC inspections for cracking of each affected tension tie and of the surrounding structure, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 747-53-2502, dated April 21, 2005; or Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010. If any cracking is found: Before further flight, do all applicable corrective and related investigative actions. Do all actions in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 747-53-2502, dated April 21, 2005; or Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010. Where Boeing Special Attention Service Bulletin 747-53-2502, dated April 21, 2005; or Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010; specify to contact Boeing for repair instructions: Before further flight, repair the area using a method approved in accordance with the procedures specified in paragraph (n) of this AD. As of August 14, 2012 (the effective date of AD 2012-13-08, Amendment 39-17110 (77 FR 40481, July 10, 2012)), only Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010, may be used to accomplish the actions required by this paragraph. Repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles until the modification required by paragraph (j) of this AD is accomplished.
(1) For stations (STA) 780 through 940: Before the accumulation of 17,000 total flight cycles, or within 1,000 flight cycles after February 16, 2006 (the effective date of AD 2006-01-07, Amendment 39-14446 (71 FR 1947, January 12, 2006)), whichever occurs later.
(2) For STA 720, 740, and 760: At the earlier of the times specified in paragraph (h)(2)(i) or (h)(2)(ii) of this AD.
(i) Before the accumulation of 17,000 total flight cycles, or within 1,000 flight cycles after February 16, 2006 (the effective date of AD 2006-01-07, Amendment 39-14446 (71 FR 1947, January 12, 2006)), whichever occurs later.
(ii) Before the accumulation of 8,000 total flight cycles, or within 1,000 flight cycles after August 14, 2012 (the effective date of AD 2012-13-08, Amendment 39-17110 (77 FR 40481, July 10, 2012)), whichever occurs later.
This paragraph restates the requirements of paragraph (i) of AD 2012-13-08, Amendment 39-17110 (77 FR 40481, July 10, 2012). For airplanes identified in Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010, as Group 2 airplanes: Before the accumulation of 8,000 total flight cycles, or within 1,000 flight cycles after August 14, 2012 (the effective date of AD 2012-13-08), whichever occurs later, do a general visual inspection for correct configuration, as identified in Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010, of each affected tension tie and of the surrounding structure, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010.
(1) If all tension ties match the correct configurations specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010, no further work is required by this paragraph.
(2) If any incorrect configuration is found, before further flight, do detailed and open fastener-hole HFEC inspections for cracking in the tension tie and frame, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010.
(i) If no crack is found during the inspections required by paragraph (i)(2) of this AD: Before further flight, install the correct configuration for the tension ties at locations where the incorrect configuration was found, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010; except where Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010, specifies to contact Boeing for installation instructions, use a method approved in accordance with the procedures specified in paragraph (n) of this AD.
(ii) If any crack is found during the inspections required by paragraph (i)(2) of this AD, before further flight, do the actions specified in paragraphs (i)(2)(ii)(A) and (i)(2)(ii)(B) of this AD.
(A) Repair the crack in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010; except where Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010, specifies to contact Boeing for appropriate action, before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (n) of this AD.
(B) Install the correct configuration for the tension ties at locations where the incorrect configuration was found, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010; except where Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010, specifies to contact Boeing for installation instructions, use a method approved in accordance with the procedures specified in paragraph (n) of this AD.
(1) For Groups 1 through 16, Configuration 1, airplanes identified in Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013: At the applicable compliance time specified in table 1 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013, except as required by paragraph (l)(1) of this AD, do tension tie and frame modifications, in accordance with Part 1, and surface HFEC inspections for cracks, in accordance with Part 4, of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013. Accomplishment of these modifications terminates the repetitive inspections required by paragraphs (g) and (h) of this AD. If any crack is found, before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (n) of this AD.
(2) For Groups 17 and 18 airplanes identified in Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013: At the applicable time specified in table 6 or table 7, as applicable, of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013, do a tension tie and frame modification (replacement of tension ties and frame structure), in accordance with Part 5 or Part 6, as applicable, of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013. Accomplishment of these modifications terminates the repetitive inspections required by paragraph (g) of this AD.
(1) For Groups 1 through 16 airplanes identified in Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013: At the applicable time specified in table 2 or table 3 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013, do a detailed inspection for cracking in the unmodified areas of the tension ties, in accordance with Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013. If any cracking is found, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (n) of this AD. Repeat the detailed inspection thereafter at the applicable time specified in table 2 or table 3 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013.
(2) For Groups 1 through 16 airplanes identified in Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013: At the applicable time specified in table 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013, do eddy current inspections for cracking in all areas of the tension ties (modified and unmodified), in accordance with Part 3 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013. If any cracking is found, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (n) of this AD. Repeat the eddy current inspections thereafter at the time specified in table 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013.
(3) For Groups 1 through 16, Configuration 2, airplanes identified in Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013: At the applicable time specified in table 5 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013, except as provided by paragraph (l)(1) of this AD, do surface HFEC inspections for cracking in the unmodified tension tie center sections, in accordance with Part 4 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013. If any cracking is found, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (n) of this AD. If no cracking is found, no further action is required until the repetitive inspections required by paragraphs (k)(1) and (k)(2) begin.
(4) For Groups 17 and 18 airplanes identified in Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013: At the applicable time specified in table 6 or table 7 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013, do detailed and HFEC inspections of the modified tension tie and frame structure for cracking, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2502, Revision 1, dated June 17, 2010. Except as required by paragraph (l)(4) of this AD, if any cracking is found, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (n) of this AD. Repeat the detailed and HFEC inspections thereafter at the times specified in table 6 or table 7, as applicable, of Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013.
(1) Where paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013, specifies a compliance time “after the revision 3 date of this service bulletin,” this AD requires compliance within the specified time after the effective date of this AD.
(2) Where Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013, specifies to contact Boeing for repair instructions, this AD requires repair before further flight using a method approved in accordance with the procedures specified in paragraph (n) of this AD.
(3) Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013, refers to Section 51-10-02 of the Boeing 747-400F Structural Repair Manual (SRM) and Section 51-10-01 of the Boeing 747-100/200/300 SRM as additional sources of guidance for removing small cracks and fatigue damage material from the existing holes in the unmodified center section of the tension tie channels. Where those SRM sections state that “zero-timing must only be used where specifically permitted in an SRM chapter-section-repair,” this AD allows the zero-timing procedures specified in those SRM sections.
(4) Where Boeing Alert Service Bulletin 747-53A2605, Revision 3, dated July 10, 2013, specifies to contact Boeing for repair instructions, this AD requires repair before further flight using a method approved in accordance with the procedures specified in paragraph (n) of this AD.
