Airworthiness Directive · Amendment 39-16247 · Fuselage
The Boeing Company Model 747-200C and -200F Series Airplanes
This AD applies to The Boeing Company Model 747-200C and -200F series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 747-53A2439, Revision 2, dated July 17, 2008.
The FAA is superseding an existing airworthiness directive (AD), which applies to certain Model 747-200C and -200F series airplanes. That AD currently requires repetitive inspections to find fatigue cracking in the floor panel attachment fastener holes of the upper chord of certain upper deck floor beams in Section 41 (i.e., body station 520 and forward), and repair if necessary. The existing AD also provides optional modifications, which extend the threshold for initiating certain repetitive inspections. This new AD requires additional repetitive inspections to find fatigue cracking in the floor panel attachment fastener holes of the upper chord of certain other upper deck floor beams in Section 41 and Section 42 (i.e., aft of body station 520); repetitive inspections to find fatigue cracking in the permanent fastener holes of the upper chord of certain upper deck floor beams in Section 41; and related investigative and corrective actions. This new AD also provides a new optional modification, which terminates certain repetitive inspections. This AD results from new reports of cracking in the upper chord of the upper deck floor beams in Sections 41 and 42, and new analysis that shows the permanent fastener holes of the upper chord of certain upper deck floor beams in Section 41 are also susceptible to fatigue cracking. We are issuing this AD to detect and correct cracking in the upper chord of the upper deck floor beams. Such cracking could extend and sever the floor beams, which could result in rapid decompression and loss of controllability of the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
At the earliest of the times specified in paragraphs (g)(1) through (g)(3) of this AD, do the inspection required by paragraph (h) of this AD.
(1) Before the accumulation of 22,000 total flight cycles, or within 1,000 flight cycles after March 15, 2004 (the effective date of AD 2004-03-11, which was superseded by AD 2006-08-02), whichever occurs later.
(2) For airplanes with 17,000 or more total flight cycles as of May 17, 2006 (the effective date of AD 2006-08-02): Before the accumulation of 18,000 total flight cycles, or within 90 days after May 17, 2006, whichever occurs later.
(3) For airplanes with fewer than 17,000 total flight cycles as of May 17, 2006: Before the accumulation of 15,000 total flight cycles, or within 1,000 flight cycles after May 17, 2006, whichever occurs later.
Do the applicable inspection to find fatigue cracking in the upper chord of the upper deck floor beams as specified in Part 1 (Open-Hole High Frequency Eddy Current (HFEC) Inspection Method) or Part 2 (Surface HFEC Inspection Method) of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001. Do the inspections per the Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001, except as provided by paragraph (k) of this AD. Any combination of the applicable inspection methods specified in Parts 1 and 2 may be used, provided that the corresponding repetitive inspection interval is used.
(1) If any crack is found, before further flight, repair per Part 3 (Upper Chord Repair) of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001; except where Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001, specifies to contact Boeing for appropriate action, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (o) of this AD or repair according to data meeting the certification basis of the airplane approved by a Boeing Company Designated Engineering Representative (DER) or by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization. For a repair method to be approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, as required by this paragraph, the Manager's approval letter must specifically reference this AD. Do the applicable inspection of the repaired area per Part 1 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001, at the applicable time per Part 3 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001, and repeat the applicable inspection at the applicable interval per Figure 1 of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001.
(2) If no crack is found, repeat the applicable inspection per paragraph (h) of this AD at the applicable time specified in paragraphs (h)(2)(i) through (h)(2)(iii) of this AD. As an option to the repetitive inspections, accomplishment of paragraph (i)(1) or (i)(2) of this AD, before further flight, extends the threshold for the initiation of the repetitive inspections required by this paragraph.
(i) If the immediately preceding inspection was conducted using an open-hole HFEC inspection method: Conduct the next inspection of that area within 3,000 flight cycles of the last inspection.
(ii) If the immediately preceding inspection was conducted using a surface HFEC inspection method at stations 340 through 420 inclusive and station 500: Conduct the next inspection of that area within 750 flight cycles of the last inspection.
(iii) If the immediately preceding inspection was conducted using a surface HFEC inspection method at stations 440 and 520: Conduct the next inspection of that area at the earlier of the times specified in paragraphs (h)(2)(iii)(A) and (h)(2)(iii)(B) of this AD, and thereafter at intervals not to exceed 250 flight cycles.
(A) Within 750 flight cycles since the last surface HFEC inspection required by paragraph (h) of this AD.
(B) Within 250 flight cycles after May 17, 2006.
(i) For areas on which the inspection required by paragraph (h) of this AD is done per Part 1 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001; and on which no cracking is found: Accomplishment of the actions specified in either paragraph (i)(1) or (i)(2) of this AD extends the threshold for the initiation of the repetitive inspections required by paragraph (h)(2) of this AD. For areas on which the inspection required by paragraph (h) of this AD is done per Part 2 of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001; and on which no cracking is found: Accomplishment of the actions specified in paragraph (i)(1) of this AD extends the threshold for the initiation of the repetitive inspections required by paragraph (h)(2) of this AD.
(1) Do the applicable repair per Part 3 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001, except as provided by paragraph (k) of this AD. At the applicable time specified in Table 1 of Part 3 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001, do the applicable inspection of the repaired area per Part 1 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001. Repeat the inspection thereafter within the applicable interval of 3,000 flight cycles per Figure 1 of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001.
(2) Do the modification of the attachment hole of the floor panel per Figure 5 of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001, except as provided by paragraph (k) of this AD. Within 10,000 flight cycles after accomplishment of the modification, do the inspection of the modified area per Part 1 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001. Repeat the inspection thereafter within the applicable interval of 3,000 flight cycles per Figure 1 of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001.
For the purposes of calculating the compliance threshold and repetitive intervals for actions required by paragraph (g), (h), or (i) of this AD: As of May 17, 2006 (the effective date of AD 2006-08-02), all flight cycles, including the number of flight cycles in which cabin differential pressure is at 2.0 pounds per square inch (psi) or less, must be counted when determining the number of flight cycles that have occurred on the airplane.
Use the information in Tables 1 and 2 of this AD, at the applicable time specified in paragraphs (k)(1) and (k)(2) of this AD, to determine the part of the applicable service bulletin to use to accomplish the actions required by this AD.
(1) On or after May 17, 2006, but before the effective date of this AD, use only the service information listed in Table 1 or Table 2 of this AD.
| Do— | In accordance with— |
|---|---|
| (1) The actions required by paragraph (h) of this AD | Parts 1 and 2 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005; as applicable. |
| (2) The applicable inspection of the repaired area required by paragraph (h)(1) of this AD | Parts 1 and 6 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005; as applicable; at the applicable time specified in Table 1 of Part 3 of the Work Instructions of that service bulletin. |
| (3) The actions required by paragraph (i)(1) of this AD | Parts 1, 3, and 6 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005; as applicable. |
| (4) The actions required by paragraph (i)(2) of this AD | Figure 5 and Part 1 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005; as applicable. |
(2) On or after the effective date of this AD, use only the service information listed in Table 2 of this AD.
| Do— | In accordance with— |
|---|---|
| (1) The actions required by paragraph (h) and (l) of this AD | Part 1 (open-hole or surface HFEC inspection, as applicable) of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 2, dated July 17, 2008. |
| (2) The applicable inspection of the repaired area required by paragraph (h)(1) of this AD | Part 1 (open-hole HFEC inspection only) and Part 5 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 2, dated July 17, 2008; at the applicable time specified in Table 1 of Part 2 of the Work Instructions of that service bulletin. |
| (3) The applicable repair required by paragraph (h)(1) of this AD | Part 2 (upper chord repair at floor panel attach holes) of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 2, dated July 17, 2008. |
| (4) The actions required by paragraph (i)(1) of this AD | Part 1 (open-hole HFEC inspection only), Part 2, and Part 5 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 2, dated July 17, 2008. |
| (5) The actions required by paragraph (i)(2) of this AD | Figure 5 and Part 1 (open-hole HFEC inspection only) of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 2, dated July 17, 2008. |
For all airplanes, except as provided by paragraphs (k)(1) and (k)(2) of this AD: At the applicable time specified in Paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2439, Revision 2, dated July 17, 2008, do the applicable open-hole or surface HFEC inspections for fatigue cracking in the upper chord of the upper deck floor beams in Area 5, and the inspection for fatigue cracking in the permanent fastener holes of the upper chord of certain upper deck floor beams in Areas 1, 2, 3, and 4, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 2, dated July 17, 2008. Do all applicable related investigative and corrective actions before further flight. Repeat the applicable inspection thereafter at the applicable interval specified in Paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2439, Revision 2, dated July 17, 2008.
(1) Where Boeing Alert Service Bulletin 747-53A2439, Revision 2, dated July 17, 2008, specifies a compliance time relative to the date of issuance of that service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD.
(2) Where Boeing Alert Service Bulletin 747-53A2439, Revision 2, dated July 17, 2008, specifies contacting Boeing for repair data: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (o) of this AD.
For areas 1, 2, 3, and 4 as defined in Boeing Alert Service Bulletin 747-53A2439, Revision 2, dated July 17, 2008: Doing the modification and post-modification actions specified in Boeing Alert Service Bulletin 747-53A2696, dated October 16, 2008, terminates the repetitive inspection requirements of paragraphs (g) and (h) of this AD. Doing the modification and post-modification actions specified in Boeing Alert Service Bulletin 747-53A2696, dated October 16, 2008, terminates the repetitive inspection requirements of paragraph (l) of this AD, except at the upper deck floor beam at body station (BS) 460 and 480 and the upper deck floor beams aft of BS 520.
Although Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005; and Boeing Alert Service Bulletin 747-53A2439, Revision 2, dated July 17, 2008; specify to submit certain information to the manufacturer, this AD does not include that requirement.
