Airworthiness Directive · Amendment 39-17110 · Fuselage
The Boeing Company Airplanes
Superseded. A later AD replaced this one: AD 2014-22-11. Comply with the one in force.
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 an existing airworthiness directive (AD) 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. That AD currently requires repetitive inspections for cracks of each affected tension tie and of the surrounding structure, and related investigative and corrective actions if necessary. This new AD requires, for certain airplanes, modifying the tension tie structure or tension tie and frame structure at certain stations; and a post-modification inspection of the modified area and post-modification repetitive inspections of the unmodified area, and repair if necessary. Doing the modification would terminate the repetitive inspection requirements in the existing AD. This AD reduces the compliance time and adds inspections for certain airplanes. This AD was prompted by reports that certain airplanes have tension ties that are susceptible to widespread fatigue damage. This AD also results from reports of cracks on the forward and aft tension tie channels at station (STA) 740 and STA 760, and a determination that initial inspection intervals need to be reduced. We are issuing this AD to prevent tension ties from becoming severed or disconnected from the frames, which could lead to rapid in-flight decompression.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
This paragraph restates the requirements of paragraph (f) of AD 2006-01-07, Amendment 39-14446 (71 FR 1947, January 12, 2006), with reduced compliance time for certain airplanes and revised service information. 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 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 the effective date of this AD, 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 Group 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 (f) of AD 2006-01-07, Amendment 39-14446 (71 FR 1947, January 12, 2006), with reduced compliance time for certain airplanes and revised service information. 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 high-frequency eddy current 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 the effective date of this AD, 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 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 the effective date of this AD, whichever occurs later.
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 the effective date of this AD, 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 high frequency eddy current inspections for cracks 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 inspection 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 inspection 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.
Before the accumulation of 30,000 total flight cycles, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later: Modify the left- and right-side tension tie structure or left- and right-side tension tie and frame structure, at specified stations, in accordance with the applicable method specified in paragraph (j)(1) or (j)(2) of this AD. Accomplishment of the modification in this paragraph terminates the repetitive inspection requirements in paragraphs (g)(1), (g)(2), and (h) of this AD.
(1) For airplanes identified in Boeing Alert Service Bulletin 747-53A2605, Revision 1, dated May 27, 2010: Do the modification in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2605, Revision 1, dated May 27, 2010.
(2) For airplanes not identified in Boeing Alert Service Bulletin 747-53A2605, Revision 1, dated May 27, 2010: Do the modification using a method approved in accordance with the procedures specified in paragraph (n) of this AD.
Note 1 to paragraph (j)(2) of this AD: For airplanes identified in paragraph (j)(2) of this AD, post-modification inspection guidance may be included in an approved alternative method of compliance (AMOC) for paragraph (j)(2) of this AD.
For airplanes identified in paragraph (j)(1) of this AD, within 20,000 flight cycles after doing the modification required by paragraph (j) of this AD: Do an inspection for cracks of the modified areas of the left- and right-side tension tie structure and frame structure, in accordance with a method approved in accordance with the procedures specified in paragraph (n) of this AD. If any crack is found during any inspection required by this paragraph, before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (n) of this AD.
(1) For airplanes identified in paragraph (j)(1) of this AD, within 6,000 flight cycles after doing the modification required by paragraph (j) of this AD: Do a detailed inspection for cracks on the unmodified areas of the left- and right-side tension tie structure and frame structure, at certain stations, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2605, Revision 1, dated May 27, 2010. If any crack is found during any inspection required by this paragraph, before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (n) of this AD. Repeat the inspection of the unmodified areas thereafter at intervals not to exceed 6,000 flight cycles.
(2) Boeing Alert Service Bulletin 747-53A2605, Revision 1, dated May 27, 2010, 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.
