96-23-02 BOEING: Amendment 39-9807. Docket 96-NM-251-AD. \n\n\tApplicability: Model 747 series airplanes; line numbers 1 through 200 inclusive on which the skin panel replacement specified in Boeing Service Bulletin 747-53A2321 has been accomplished; line numbers 201 through 430 inclusive that have been modified by Boeing to a Stretched Upper Deck (SUD) configuration; and line numbers 431 through 1075 inclusive; certificated in any category. \n\n\tNOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (u) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent rapid decompression of the airplane due to disbonding and subsequent cracking of the skin panels, accomplish the following: Disallowance of Adjustment Factor: \n\n\t(a)\tFor Model 747SR and 747-400 series airplanes operating at a cabin \ndifferential pressure lower than 8.9 pounds per square inch (psi): An adjustment factor of 1.2 shall not be used as a multiplier for thresholds and intervals specified in Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996. Initial Inspection of Area 1: \n\n Group 1 Airplanes \n\n\t(b)\tFor airplanes identified as Group 1 in Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996, on which the skin panel replacement specified in Boeing Alert Service Bulletin 747-53A2321 has been accomplished: Perform an inspection to detect disbonding, corrosion, and/or cracking of the skin at the location specified as Area 1 in Table 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996, using an inspection technique identified as Method 1, 2, 3, or 4 in paragraph A., Part I, of the Accomplishment Instructions of the alert service bulletin. Accomplish the inspection at the time specified in paragraph (b)(1) or (b)(2) of this AD, as applicable. In any case, any inspection using Method 1 or 2 shall not be accomplished prior to the accumulation of 2,000 total flight cycles with cabin differential pressure above 2.0 psi since skin panel replacement in accordance with Boeing Alert Service Bulletin 747-53A2321. If inspection Method 1 or 2 is used and no disbonded doubler is found, no further action is required by this AD. \n\n\t\t(1)\tFor airplanes on which zones 1 and 2 of the fuselage havenot been modified in accordance with Boeing Service Bulletin 747-53-2272: Inspect at the later of the times specified in paragraphs (b)(1)(i) and (b)(1)(ii) of this AD. \n\n\t\t\t(i)\tPrior to the accumulation of 8,000 total flight cycles, or within 150 flight cycles after the effective date of this AD, whichever occurs later. \n\n\t\t\t(ii)\tWithin 60 days after the effective date of this AD. \n\t\t(2)\tFor airplanes on which zones 1 and 2 of the fuselage have been modified in accordance with Boeing Service Bulletin 747-53-2272: Inspect at the later of the times specified in paragraphs (b)(2)(i) and (b)(2)(ii) of this AD. \n\n\t\t\t(i)\tPrior to the accumulation of 10,000 total flight cycles, or within 150 flight cycles after the effective date of this AD, whichever occurs later. \n\n\t\t\t(ii)\tWithin 60 days after the effective date of this AD. \n\nOn-Condition Repairs and Repetitive Inspections: Group 1 Airplanes \n\n\t(c)\tIf inspection Method 1 or 2 was used to accomplish the inspection required by paragraph (b) of this AD, and any disbonded doubler was found during that inspection: Prior to further flight, perform external detailed visual inspections (Method 3) or external HFEC inspections (Method 4) to detect cracking of the fuselage skin in the areas where the disbonded doubler was found, in accordance with Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996. \n\n\t\t(1)\tIf inspection Method 3 was used to accomplish the inspection required by paragraph (c) of this AD, and no cracking was found during the inspection: Repeat the inspection thereafter at intervals not to exceed 150 flight cycles for up to 1,000 flight cycles; thereafter, perform external HFEC inspections (Method 4) at intervals not to exceed 2,000 flight cycles in accordance with the alert service bulletin. \n\n\t\t(2)\tIf inspection Method 4 was used to accomplish the inspection required by paragraph (c) of this AD, and no cracking was found during the inspection: Repeat the inspection thereafterat intervals not to exceed 2,000 flight cycles in accordance with the alert service bulletin. \n\n\t(d)\tIf inspection Method 3 was used to accomplish the inspection required by paragraph (b) of this AD, and no cracking was found during the inspection: Repeat the inspection thereafter at intervals not to exceed 150 flight cycles for up to 1,000 flight cycles; thereafter, accomplish either paragraph (d)(1) or (d)(2) of this AD in accordance with Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996. \n\n\t\t(1)\tPerform a one-time inspection using Method 1 or 2; or \n\n\t\t(2)\tPerform repetitive inspections using inspection Method 4 at intervals not to exceed 2,000 flight cycles. \n\n\t(e)\tIf inspection Method 4 was used to accomplish the inspection required by paragraph (b) of this AD, and no cracking was found during the inspection: Repeat the inspection thereafter at intervals not to exceed 2,000 flight cycles in accordance with Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996. \n\n\t(f)\tIf any cracking is found during any inspection required by paragraphs (b), (c), (d), or (e) of this AD, and the cracking is within the limits specified in Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996, prior to further flight, repair in accordance with the alert service bulletin. Following repair, perform repetitive inspections using inspection Method 4 thereafter at intervals not to exceed 2,000 flight cycles in accordance with the alert service bulletin. \n\n\t(g)\tIf any cracking is found during any inspection required by paragraphs (b), (c), (d), or (e) of this AD, and the cracking is outside the limits specified in Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996, prior to further flight, repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. \n\nInitial Inspection of Areas 1 and 4: Groups 2, 3, 6, and 8 Airplanes \n\n\t(h)For airplanes identified as Group 2, 3, 6, or 8 in Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996: Perform inspections to detect disbonding, corrosion, and/or cracking of the skin at the locations specified as Areas 1 and 4 in Table 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996, using an inspection technique identified as Method 1, 2, 3, or 4 (for Area 1), or Method 2, 3, or 4 (for Area 4) in paragraph A., Part I, of the Accomplishment Instructions of the alert service bulletin. Accomplish the inspection at the time specified in paragraph (h)(1) or (h)(2) of this AD, as applicable. In any case, any inspection using Method 1 or 2 shall not be accomplished prior to the accumulation of 2,000 total flight cycles with cabin differential pressure above 2.0 psi since delivery, or since modification to the SUD configuration. If inspection Method 1 or 2 is used and no disbonded doubler is found, no further action is required by this AD. \n\n\t\t(1)\tFor airplanes on which zones 1, 2, and 3 of the fuselage have not been modified in accordance with Boeing Service Bulletin 747-53-2272: Inspect at the later of the times specified in paragraphs (h)(1)(i) and (h)(1)(ii) of this AD. \n\n\t\t\t(i)\tPrior to the accumulation of 8,000 total flight cycles, or within 150 flight cycles after the effective date of this AD, whichever occurs later. \n\n\t\t\t(ii)\tWithin 60 days after the effective date of this AD. \n\n\t\t(2)\tFor airplanes on which zones 1, 2, and 3 of the fuselage have been modified in accordance with Boeing Service Bulletin 747-53-2272: Inspect at the later of the times specified in paragraphs (h)(2)(i) and (h)(2)(ii) of this AD. \n\n\t\t\t(i)\tPrior to the accumulation of 10,000 total flight cycles, or within 150 flight cycles after the effective date of this AD, whichever occurs later. \n\n\t\t\t(ii)\tWithin 60 days after the effective date of this AD.\n\n On-Condition Repairs and Repetitive Inspections: Groups 2, 3, 6, and 8 Airplanes \n\n\t(i)\tIf inspection Method 1 or 2 was used to accomplish the inspection required by paragraph (h) of this AD, and any disbonded doubler was found during that inspection: Prior to further flight, perform external detailed visual inspections (Method 3) or external HFEC inspections (Method 4) to detect cracking of the fuselage skin in the areas where the disbonded doubler was found, in accordance with Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996. \n\n\t\t(1)\tIf inspection Method 3 was used to accomplish the inspection required by paragraph (i) of this AD, and no cracking was found during the inspection: Repeat the inspection thereafter at intervals not to exceed 150 flight cycles (for Area 1) or 250 flight cycles (for Area 4), as applicable, for up to 1,000 flight cycles; thereafter, perform external HFEC inspections (Method 4) at intervals not to exceed 2,000 flight cycles (for Area 1) or 3,000 flight cycles (for Area 4), as applicable, in accordance with the alert service bulletin. \n\n\t\t(2)\tIf inspection Method 4 was used to accomplish the inspection required by paragraph (i) of this AD, and no cracking was found during the inspection: Repeat the inspection thereafter at intervals not to exceed 2,000 flight cycles (for Area 1) or 3,000 flight cycles (for Area 4), as applicable, in accordance with the alert service bulletin. \n\n\t(j)\tIf inspection Method 3 was used to accomplish the inspection required by paragraph (h) of this AD, and no cracking was found during the inspection: Repeat the inspection thereafter at intervals not to exceed 150 flight cycles (for Area 1) or 250 flight cycles (for Area 4), as applicable, for up to 1,000 flight cycles; thereafter, accomplish either paragraph (j)(1) or (j)(2) of this AD in accordance with Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996. \n\n\t\t(1)\tPerform a one-time inspection using Method 1 or 2 (for Area 1), or Method 2 (for Area 4 only);or \n\n\t\t(2)\tPerform repetitive inspections using inspection Method 4 at intervals not to exceed 2,000 flight cycles (for Area 1) or 3,000 flight cycles (for Area 4), as applicable. \n\n\t(k)\tIf inspection Method 4 was used to accomplish the inspection required by paragraph (h) of this AD, and no cracking was found during the inspection: Repeat the inspection thereafter at intervals not to exceed 2,000 flight cycles (for Area 1) or 3,000 flight cycles (for Area 4), as applicable, in accordance with Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996. \n\n\t(l)\tIf any cracking is found during any inspection required by paragraphs (h), (i), (j), or (k) of this AD, and the cracking is within the limits specified in Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996, prior to further flight, repair in accordance with the alert service bulletin. Following repair, perform repetitive inspections using inspection Method 4 thereafter at intervals not to exceed 2,000 flight cycles (for Area 1) or 3,000 flight cycles (for Area 4), as applicable, in accordance with the alert service bulletin. \n\n\t(m)\tIf any cracking is found during any inspection required by paragraphs (h), (i), (j), or (k) of this AD, and the cracking is outside the limits specified in Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996, prior to further flight, repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Initial Inspection of Areas 1 and 4: Groups 4, 5, 7, 9, and 10 Airplanes \n\n\t(n)\tFor airplanes identified as Group 4, 5, 7, 9, or 10 in Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996: Perform inspections to detect disbonding, corrosion, and/or cracking of the skin at the locations specified as Areas 1 and 4 in Table 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996, using an inspection technique identified as Method 1, 2, 3, or 4 (for Area 1) or Method 2, 3, or 4 (for Area 4) in paragraph A., Part I, of the Accomplishment Instructions of the alert service bulletin. Accomplish the inspection at the later of the times specified in paragraphs (n)(1) and (n)(2) of this AD. In any case, any inspection using Method 1 or 2 shall not be accomplished prior to the accumulation of 2,000 total flight cycles with cabin differential pressure above 2.0 psi since delivery. If inspection Method 1 or 2 is used and no disbonded doubler is found, no further action is required by this AD. \n\n\t\t(1)\tPrior to the accumulation of 10,000 total flight cycles, or within 150 flight cycles after the effective date of this AD, whichever occurs later. \n\n\t\t(2)\tWithin 60 days after the effective date of this AD.\n\nOn-Condition Repairs and Repetitive Inspections: Groups 4, 5, 7, 9, and 10 Airplanes \n\n\t(o)\tIf inspection Method 1 or 2 was used to accomplish the inspection required by paragraph (n) of this AD, and any disbonded doubler was found during that inspection: Prior to further flight, perform external detailed visual inspections (Method 3) or external HFEC inspections (Method 4) to detect cracking of the fuselage skin in the areas where the disbonded doubler was found, in accordance with Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996. \n\n\t\t(1)\tIf inspection Method 3 was used to accomplish the inspection required by paragraph (o) of this AD, and no cracking was found during the inspection: Repeat the inspection thereafter at intervals not to exceed 150 flight cycles (for Area 1) or 250 flight cycles (for Area 4), as applicable, for up to 1,000 flight cycles; thereafter, perform external HFEC inspections (Method 4) at intervals not to exceed 2,000 flight cycles (for Area 1) or 3,000 flight cycles (for Area 4), as applicable, in accordance with the alert service bulletin. \n\n\t\t(2)\tIf inspection Method 4 was used to accomplish the inspectionrequired by paragraph (o) of this AD, and no cracking was found during the inspection: Repeat the inspection thereafter at intervals not to exceed 2,000 flight cycles (for Area 1) or 3,000 flight cycles (for Area 4), as applicable, in accordance with the alert service bulletin. \n\n\t(p)\tIf inspection Method 3 was used to accomplish the inspection required by paragraph (n) of this AD, and no cracking was found during the inspection: Repeat the inspection thereafter at intervals not to exceed 150 flight cycles (for Area 1) or 250 flight cycles (for Area 4), as applicable, for up to 1,000 flight cycles; thereafter, accomplish either paragraph (p)(1) or (p)(2) of this AD in accordance with Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996. \n\n\t\t(1)\tPerform a one-time inspection using Method 1 or 2 (for Area 1), or Method 2 (for Area 4 only); or \n\n\t\t(2)\tPerform repetitive inspections using inspection Method 4 at intervals not to exceed 2,000 flight cycles (for Area 1)or 3,000 flight cycles (for Area 4), as applicable. \n\n\t(q)\tIf inspection Method 4 was used to accomplish the inspection required by paragraph (n) of this AD, and no cracking was found during the inspection: Repeat the inspection thereafter at intervals not to exceed 2,000 flight cycles (for Area 1) or 3,000 flight cycles (for Area 4), as applicable, in accordance with Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996. \n\n\t(r)\tIf any cracking is found during any inspection required by paragraphs (n), (o), (p), or (q) of this AD, and the cracking is within the limits specified in Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996, prior to further flight, repair in accordance with the alert service bulletin. Following repair, perform repetitive inspections using inspection Method 4 thereafter at intervals not to exceed 2,000 flight cycles (for Area 1) or 3,000 flight cycles (for Area 4), as applicable. \n\n\t(s)\tIf any cracking is found during anyinspection required by paragraphs (n), (o), (p), or (q) of this AD, and the cracking is outside the limits specified in Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996, prior to further flight, repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. \n\n\t(t)\tWithin 10 days after accomplishing any inspection to detect disbonding required by paragraphs (b), (d)(1), (h), (j)(1), (n), and (p)(1) this AD, report any findings of disbonding to the Manager, Seattle Manufacturing Inspection District Office, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; fax (206) 227-1159. The report shall include the information specified in paragraphs (t)(1), (t)(2), and (t)(3) of this AD. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056. \n\n\t\t(1)\tThe line number of the airplane on which disbonding was found. \n\t\t(2)\tThe number of disbonded skin panels that were found. \n\t\t(3)\tThe part number of any disbonded skin panel that is found. \n\n\t(u)\tAn alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO. \n\tNOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\n\t(v)\tSpecial flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. \n\n\t(w)\tThe actions shall be done in accordance with Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(x)\tThis amendment becomes effective on November 27, 1996.