Airworthiness Directive · Amendment 39-14812 · Boeing Model 747 Airplanes
Boeing Model 747 Airplanes
Superseded. A later AD replaced this one: AD 2016-06-07. Comply with the one in force.
This AD 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, 747SR, and 747SP series airplanes, certificated in any category.
The FAA is superseding an existing airworthiness directive (AD), which applies to all Boeing Model 747 series airplanes. That AD currently requires repetitive inspections for cracking of the top and side panel webs and panel stiffeners of the nose wheel well (NWW), and corrective actions if necessary. This new AD reduces the interval for certain repetitive inspections and removes a certain optional inspection. This new AD also requires replacing the NWW side and top panels with new panels, which terminates the repetitive inspections. This AD results from the development of a new modification. We are issuing this AD to prevent fatigue cracks in the top and side panel webs and stiffeners of the NWW, which could compromise the structural integrity of the NWW and could lead to the rapid decompression 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.
Prior to the accumulation of 16,000 total flight cycles, or within 1,000 flight cycles after January 27, 2005 (the effective date of AD 2004-25-23, amendment 39-13911), whichever is later, do internal detailed and surface high frequency eddy current (HFEC) inspections of the top and side panel stiffeners of the NWW (specified as Area 3 in the service bulletin) for cracks in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin (ASB) 747-53A2465, Revision 4, dated February 24, 2005. Repeat the inspections thereafter at the compliance times specified in paragraph (f)(1) or (f)(2) of this AD, as applicable.
(1) For airplanes on which an inspection has not been done before the effective date of this AD in accordance with any service bulletin listed in Table 1 of this AD: Within 1,500 flight cycles after doing the inspection specified in paragraph (f) of this AD, repeat the inspection. Repeat the inspection thereafter at intervals not to exceed 1,500 flight cycles.
(2) For airplanes on which an inspection has been done before the effective date of this AD in accordance with any service bulletin listed in Table 1 of this AD: Within 6,000 flight cycles after doing the inspection specified in paragraph (f) of this AD or within 1,500 flight cycles after the effective date of this AD, whichever occurs first, repeat the inspection. Repeat the inspection thereafter at intervals not to exceed 1,500 flight cycles.
| Service bulletin | Revision level | Date |
|---|---|---|
| Boeing ASB 747-53A2465 | Original | April 5, 2001. |
| Boeing ASB 747-53A2465 | 2 | November 11, 2004. |
| Boeing ASB 747-53A2465 | 3 | December 23, 2004. |
| Boeing ASB 747-53A2465 | 4 | February 24, 2005. |
| Boeing Service Bulletin 747-53A2465 | 1 | October 16, 2003. |
Note 1: For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”
Do an external detailed inspection of the top and sidewall panel webs of the NWW (specified as Area 1 and Area 2 in the service bulletin) for cracks, in accordance with the Accomplishment Instructions of Boeing ASB 747-53A2465, Revision 4, dated February 24, 2005, at the earlier of the times specified in paragraphs (g)(1) and (g)(2) of this AD.
(1) At the later of the times specified in paragraph (g)(1)(i) and (g)(1)(ii) of this AD:
(i) Before accumulating 20,000 total flight cycles.
(ii) Within 100 flight cycles or 90 days after May 10, 2005 (the effective date of AD 2005-09-02), whichever occurs first.
(2) At the later of the times specified in paragraphs (g)(2)(i) and (g)(2)(ii) of this AD:
(i) Before accumulating 16,000 total flight cycles.
(ii) Within 1,000 flight cycles after May 10, 2005.
Repeat the inspection required by paragraph (g) of this AD at the intervals specified in paragraphs (h)(1) and (h)(2) of this AD, as applicable.
(1) For airplanes with fewer than 20,000 total flight cycles as of May 10, 2005, repeat at intervals not to exceed 1,000 flight cycles until the first inspection after the airplane reaches 20,000 total flight cycles.
(2) For airplanes with 20,000 total flight cycles or more, repeat at intervals not to exceed 500 flight cycles.
(i) Do an UT inspection of the top and sidewall panel webs for cracks, in accordance with Boeing ASB 747-53A2465, Revision 4, dated February 24, 2005, at the later of the times specified in paragraphs (i)(1) and (i)(2) of this AD. Repeat the inspections thereafter at intervals not to exceed 500 flight cycles.
(1) Prior to the accumulation of 20,000 total flight cycles.
(2) Within 100 flight cycles or 90 days after May 10, 2005, whichever occurs first.
Except as specified in paragraph (l) of this AD, if any crack is found during any inspection required by this AD, prior to further flight, do any applicable additional detailed inspections of stiffeners and beams and make repairs, in accordance with the Accomplishment Instructions of Boeing ASB 747-53A2465, Revision 4, dated February 24, 2005.
The actions specified in paragraphs (k)(1), (k)(2), and (k)(3) of this AD are acceptable for compliance with the corresponding action specified in the applicable paragraph.
(1) Inspections and corrective actions accomplished before January 27, 2005, in accordance with Boeing ASB 747-53A2465, dated April 5, 2001, are considered acceptable for compliance with the corresponding inspections specified in paragraph (f) of this AD.
(2) Inspections accomplished before the effective date of this AD, in accordance with Boeing Service Bulletin 747-53A2465, Revision 1, dated October 16, 2003; Boeing ASB 747-53A2465, Revision 2, dated November 11, 2004; and Boeing ASB 747-53A2465, Revision 3, dated December 23, 2004; are considered acceptable for compliance with the corresponding inspections specified in paragraph (f) of this AD.
Note 2: The detailed and surface HFEC inspections of the top and side panel stiffeners of the NWW specified in Boeing ASB 747-53A2465, dated April 5, 2001; and Boeing Service Bulletin 747-53A2465, Revision 1, dated October 16, 2003; are acceptable for compliance with the internal detailed and surface HFEC inspections specified in paragraph (f) of this AD. (3) Inspections and corrective actions accomplished before May 10, 2005, in accordance with Boeing Service Bulletin 747-53A2465, Revision 1, dated October 16, 2003; Boeing ASB 747-53A2465, Revision 2, dated November 11, 2004; and Boeing ASB 747-53A2465, Revision 3, dated December 23, 2004; are considered acceptable for compliance with the corresponding inspections specified in paragraphs (g) and (h) of this AD.
Where Boeing Service Bulletin and ASB 747-53A2465 specify contacting the manufacturer if certain cracking is found, this AD requires, before further flight, repairing the cracking using a method approved in accordance with the procedures specified in paragraph (p) of this AD.
Although Boeing Service Bulletin and ASB 747-53A2465 specify that operators should report inspection results to the manufacturer, this AD does not require those inspection results to be reported.
For Group 1 and 3 airplanes identified in Boeing Service Bulletin 747-53A2562, Revision 1, dated July 28, 2005: Before accumulating 22,000 total flight cycles or within 48 months after the effective date of this AD, whichever occurs later, replace the NWW side and top panels with new panels in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-53A2562, Revision 1, dated July 28, 2005. Doing the replacement terminates the requirements of this AD.
(o) For Group 2 airplanes identified in Boeing Service Bulletin 747-53A2562, Revision 1, dated July 28, 2005, and Model 747 airplanes not identified in the service bulletin: Before accumulating 22,000 total flight cycles or within 57 months after the effective date of this AD, whichever occurs later, replace the NWW side and top panels using a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA. Doing the replacement terminates the requirements of this AD.
