Airworthiness Directive · Amendment 39-16442 · Fuselage
The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR Series Airplanes
Superseded. A later AD replaced this one: AD 2013-17-08. Comply with the one in force.
This AD applies to The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR series airplanes, certificated in any category, having line numbers 1 through 1419 inclusive; except for Model 747-400 series airplanes that have been modified into the 747-400 large cargo freighter configuration.
The FAA is superseding an existing airworthiness directive (AD), which applies to all Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747- 400F, and 747SR series airplanes. That AD currently requires repetitive inspections to find cracking of the web, strap, inner chords, and inner chord angle of the forward edge frame of the number 5 main entry door cutouts, and repair, if necessary. This new AD requires expanding the inspection areas to include the frame segment between stringers 16 and 23. This AD reinstates the repetitive inspections specified above for certain airplanes. This AD also requires repetitive inspections for cracking of repairs. This AD results from additional reports of cracks that have been found in the strap and inner chord of the forward edge frame of the number 5 main entry door cutouts, between stringers 16 and 23. We are issuing this AD to detect and correct such cracks. This condition, if not corrected, could cause damage to the adjacent body structure, which could result in depressurization of the airplane in flight.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
For airplanes having line numbers 1 through 1304 inclusive: Inspect the airplane for cracks between stringers 23 and 31 per Boeing Alert Service Bulletin 747-53A2450, Revision 2, including Appendix A, dated January 4, 2001; or Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009; at the later of the times specified in either paragraph (h) or (i) of this AD, per Table 1, as follows. After the effective date of this AD, use only Revision 5 of Boeing Alert Service Bulletin 747-53A2450, to accomplish the required inspection.
| Type of inspection | Area to inspect |
|---|---|
| (1) Detailed Visual | Strap inner chords forward and aft of the web, and exposed web adjacent to the inner chords on station 2231 frame from stringer 23 through 31 per Figure 5 or Figure 6 of the service bulletin, as applicable. |
| (2) Surface High Frequency Eddy Current (HFEC) | Station 2231 inner chord angles at lower main sill interface per Figure 5 or Figure 6 of the service bulletin, as applicable. |
| (3) Open Hole HFEC | Station 2231 frame fastener locations per Figures 4 and 7, and either Figure 5 or 6 of the service bulletin, as applicable. |
| (4) Surface HFEC | Around fastener locations on station 2231 inner chords from stringer 23 through 31 per Figure 5 or Figure 6 of the service bulletin, as applicable. |
| (5) Low Frequency Eddy Current | Station 2231 frame strap in areas covered by the reveal per Figure 5 or Figure 6 of the service bulletin, as applicable. |
(h) Do the inspections specified in paragraph (g) of this AD at the applicable times specified in paragraph (h)(1) or (h)(2) of this AD. Repeat the inspections at intervals not to exceed 3,000 flight cycles.
(1) Do the inspections per Table 1 of this AD at the applicable time specified in the logic diagram in Figure 1 of Boeing Alert Service Bulletin 747-53A2450, Revision 2, including Appendix A, dated January 4, 2001. Where the compliance time in the logic diagram specifies a compliance time beginning, “from receipt of this service bulletin,” this AD requires that the compliance time begin “after September 12, 2001 (the effective date of AD 2001-16-02).”
(2) After the effective date of this AD, do the inspections per Table 1 of this AD at the applicable compliance time specified in paragraph 1.E., “Compliance” of the Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. Where the compliance time in Boeing Alert Service Bulletin 747-53A2450, Revision 2, including Appendix A, dated January 4, 2001, specifies a compliance time beginning, “after the date on Revision 2 of this service bulletin,” this AD requires that the compliance time begin “after September 12, 2001 (the effective date of AD 2001-16-02).”
(i) Within 3,000 flight cycles after accomplishment of the inspections specified in Figure 1 of Boeing Alert Service Bulletin 747-53A2450, dated May 4, 2000; or Revision 1, dated July 6, 2000; repeat the inspections specified in paragraph (g) of this AD at intervals not to exceed 3,000 flight cycles.
Note 1: There is no terminating action currently available for the inspections required by paragraph (g) of this AD.
Note 2: Where there are differences between the AD and Boeing Alert Service Bulletin 747-53A2450, the AD prevails.
For all airplanes: Before the accumulation of 16,000 total flight cycles, or within 1,500 flight cycles after the effective date of this AD, whichever occurs later, do a detailed inspection, an open hole high frequency eddy current (HFEC) inspection, a surface HFEC inspection, and a subsurface low frequency eddy current (LFEC) inspection for cracking of the forward edge frame of the number 5 main entry door cutouts, at station 2231, between stringers 16 and 23; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. Repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles.
Note 3: The part number of the nut for fastener code “K” in Figure 7 of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009, should be “BACN10JC3CD,” instead of “BACB30JC3CD.” In addition, the part number of the optional nut for this fastener code should be “BACN10YR3CD,” instead of “BACN10YR4CD.”
For airplanes having line numbers 1305 and on: Before 16,000 total flight cycles or within 1,500 flight cycles after the effective date of this AD, whichever occurs later, do a detailed inspection, an open hole HFEC inspection, a surface HFEC inspections, and a subsurface LFEC inspection for cracking of the forward edge frame of the number 5 main entry door cutouts, at station 2231, between stringers 23 and 31; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. Repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles.
If any crack is found during any inspection required by this AD, before further flight, repair the crack in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; in accordance with data meeting the type certification basis of the airplane approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO, to make those findings; or in accordance with Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the approval letter must specifically reference this AD. As of the effective date of this AD, repair the crack using a method approved in accordance with the procedures specified in paragraph (o) of this AD.
Except as required by paragraph (n) of this AD, for airplanes on which the forward edge frame of the number 5 main entry door cutouts, at station 2231, between stringers 16 and 31, is repaired in accordance with Boeing Alert Service Bulletin 747-53A2450: Within 3,000 flight cycles after doing the repair or within 1,500 flight cycles after the effective date of this AD, whichever occurs later, do the detailed, LFEC, and HFEC inspections of the repaired area for cracks in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. If no cracking is found, repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles. If any crack is found, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (o) of this AD. Doing the inspections specified in paragraph (m) of this AD terminates the repetitive inspections required by paragraphs (g), (h), (i), (j), and (k) of this AD for the repaired area.
(n) For any frame that is repaired in accordance with a method other than the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009, do the inspection in accordance with a method approved in accordance with the procedures specified in paragraph (o) of this AD.
