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93-10-01: 93-10-01 BOEING: Amendment 39-8580. Docket 92-NM-93-AD. Supersedes AD 93-06-03, Amendment 39-8528. \n\n\tApplicability: Model 747 series airplanes; as listed in Boeing Service Bulletin 747-52-2186, Revision 4, dated October 24, 1991, and Boeing Alert Service Bulletin 747-52A2233, dated August 29, 1991; certificated in any category. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent inadvertent in-flight opening of the lower lobe forward and aft cargo doors and the main deck side cargo door, if installed, accomplish the following: \n\n\t(a)\tWithin the next 1,800 flight hours after the effective date of this AD, or 600 flight cycles after the effective date of this AD, whichever occurs first: With no disassembly required, perform a detailed visual inspection to detect cracks in the portal latch pin support fittings on the lower lobe forward and aft cargo doors and on the main deck side cargo door, if installed and in the cargo configuration, inaccordance with Boeing Service Bulletin 747-52-2186, Revision 4, dated October 24, 1991. \n\n\t\t(1)\tRepeat the inspection required by this paragraph at intervals not to exceed 1,800 flight hours or 600 flight cycles, whichever occurs first. \n\n\t\t(2)\tIf any cracked part is found as a result of the inspections required by this paragraph, prior to further flight, replace it and check the door rigging, in accordance with the service bulletin. \n\n\t(b)\tWithin the next 12,500 flight hours after the effective date of this AD, or 2,500 flight cycles after the effective date of this AD, or within 30 months after the effective date of this AD, whichever occurs first: With no disassembly required, perform a detailed visual inspection to detect cracks in the portal latch pin support fittings on the main deck side cargo door, if installed and in the passenger configuration, in accordance with Boeing Service Bulletin 747-52-2186, Revision 4, dated October 24, 1991. \n\n\t\t(1)\tRepeat the inspectionrequired by this paragraph at intervals not to exceed 12,500 flight hours, 2,500 flight cycles, or 30 months after the immediately preceding inspection, whichever occurs first. \n\n\t\t(2)\tIf any cracked part is found as a result of the inspections required by this paragraph, prior to further flight, replace it and check the door rigging, in accordance with the service bulletin. \n\n\t(c)\tWhen converting from the passenger configuration to the cargo configuration, prior to further flight; and thereafter at intervals not to exceed 1,800 flight hours or 600 flight cycles, whichever occurs first: With no disassembly required, perform a detailed visual inspection to detect cracks in the portal latch pin support fitting assemblies of the main deck side cargo door, if installed, in accordance with Boeing Service Bulletin 747-52-2186, Revision 4, dated October 24, 1991. Prior to further flight, replace any cracked parts found, in accordance with the service bulletin. \n\n\t(d)\tWhen converting from the cargo configuration to the passenger configuration, prior to further flight; and thereafter at intervals not to exceed 12,500 flight hours, 2,500 flight cycles, or 30 months after the immediately preceding inspection, whichever occurs first: With no disassembly required, perform a detailed visual inspection to detect cracks in the portal latch pin support fitting assemblies of the main deck side cargo door, if installed, in accordance with Boeing Service Bulletin 747-52-2186, Revision 4, dated October 24, 1991. Prior to further flight, replace any cracked parts found, in accordance with the service bulletin. \n\n\t(e)\tWithin the next 25,000 flight hours after the effective date of this AD, or 5,000 flight cycles after the effective date of this AD, or within 5 years after the effective date of this AD, whichever occurs first, accomplish the requirements of paragraphs (e)(1), (e)(2), and (e)(3) of this AD, in accordance with Boeing Service Bulletin 747-52-2186, Revision 4, dated October 24, 1991. \n\n\t\t(1)\tDisassemble parts and perform a detailed visual inspection to detect cracks and corrosion in the portal latch pin support fitting assemblies/installations on the lower lobe forward and aft cargo doors and on the main deck side cargo door, if installed, in accordance with the service bulletin. If cracks or corrosion are found, prior to further flight, repair or replace any damaged parts, and check the door rigging, in accordance with the service bulletin. \n\n\t\t(2)\tInspect to verify that all H-11 steel latch fitting-to-sill bolts, BACB30MT, and corresponding nuts, BACN10HR( ), are intact and that unsealed bolts are free of corrosion, in accordance with the service bulletin. If not, prior to further flight, install new bolts, BACB30MT, and corresponding nuts, BACN10HR( ); or install the superseding BACB3OUS bolts and BACN10HR( )CD nuts, in accordance with the service bulletin. \n\n\t\t(3)\tApply sealant to the portal latch pin support fitting and attaching hardware, in accordance with the service bulletin. (Application of sealant to fittings and attaching hardware that previously have been sealed is not required by this paragraph.) \n\n\t(f)\tAccomplishment of paragraphs (e)(1), (e)(2), and (e)(3) of this AD constitutes terminating action for the repetitive inspections required by paragraphs (a)(1), (b)(1), (c), and (d) of this AD. \n\n\t(g)\tWithin the next 6,000 flight hours after the effective date of this AD, or within 18 months after the effective date of this AD, whichever occurs first: Determine the configuration of the bellcrank/cam latch assembly of the lower lobe forward and aft cargo doors and of the main deck side cargo door, if installed; and prior to further flight, perform the procedures specified in either paragraph (g)(1) or (g)(2) of this AD, as applicable, in accordance with Boeing Alert Service Bulletin 747-52A2233, dated August 29, 1991. \n\n\t\t(1)\tFor cargo doors with cam latches attached to the bellcrank by cross- bolts, accomplish one of the procedures specified in either paragraph (g)(1)(i), (g)(1)(ii), or (g)(1)(iii) of this AD: \n\n\t\t\t(i)\tReplace all bellcranks and cam latches with bellcranks and cam latches of the new part configuration in accordance with Section III., paragraph F., of the service bulletin; and perform an operational test of the door latch mechanism, in accordance with Section III., paragraph Y., of the service bulletin. Accomplishment of this paragraph constitutes terminating action for the requirements of paragraph (g) of this AD. Or \n\n\t\t\t(ii)\tInspect the bellcranks to detect corrosion, and repair or replace any corroded parts; and replace all cam latches with cam latches of the new part configuration; in accordance with Section III., paragraph G., of the service bulletin. Perform an operational test of the door latch mechanism in accordance with Section III., paragraph Y., of the service bulletin. Accomplishment of this paragraph constitutes terminating action for the requirements of paragraph (g) of this AD. Or \n\n\t\t\t(iii)\tInspect the bellcranks to detect corrosion, and repair or replace any corroded parts; and inspect the cam latches to detect cracks and corrosion and, prior to further flight, repair or replace any cracked or corroded parts; in accordance with Section III., paragraph H., of the service bulletin. Perform an operational test of the door latch mechanism in accordance with Section III., paragraph Y., of the service bulletin. If one or more of the cam latches are repaired and/or reinstalled as a result of the actions required by this paragraph, thereafter, repeat the inspections of the cam latches required by this paragraph at intervals not to exceed 25,000 flight hours or 5 years, whichever occurs first. \n\n\t\t(2)\tFor cargo doors with cam latches attached to the bellcrank by axial-bolts, accomplish one of the procedures specified in either paragraph (g)(2)(i) or (g)(2)(ii) of this AD: \n\n\t\t\t(i)\tReplace all cam latches that have cross-bolt holes with cam latches of the new part configuration, in accordance with Section III., paragraph I., of the service bulletin. Perform an operational test of the door latch mechanism in accordance with Section III., paragraph Y., of the service bulletin. Accomplishment of this paragraph constitutes terminating action for the requirements of paragraphs (g)(1)(iii) and (g)(2)(ii) of this AD. Or \n\n\t\t\t(ii)\tIf the cam latches do not have cross-bolt holes, they may be reinstalled. If the cam latches have cross-bolt holes, inspect those latches to detect cracks; replace any cracked cam latches; and reinstall any cam latches that are not cracked; in accordance with Section III., paragraph J., of the service bulletin. Perform an operational test of the door latch mechanism in accordance with Section III., paragraph Y., of the service bulletin. If one or more of the cam latches that have cross-bolt holes is reinstalled as a result of the actions required by this paragraph, thereafter, repeat the inspections of the cam latches required by this paragraph at intervals not to exceed 25,000 flight hours or 5 years, whichever occurs first. \n\n\t(h)\tAccomplishment of the procedures specified in either paragraph (h)(1) or (h)(2) of this AD, in accordance with Boeing Alert Service Bulletin 747-52A2233, dated August 29, 1991, constitutes terminating action for the requirements of paragraph (g) of this AD. \n\n\t\t(1)\tIf one or more of the cam latches on the lower lobe forward and aft cargo doors and main deck side cargo door was repaired and/or reinstalled in accordance with paragraph (g)(1)(iii) of this AD, replace those cam latches with cam latches of the new part configuration, in accordance with Section III. of the service bulletin. Prior to further flight, perform an operational test of the door latch mechanism in accordance with Section III., paragraph Y., of the service bulletin. Or \n\n\t\t(2)\tIf one or more of the cam latches that have cross-bolt holes on the lower lobe forward and aft cargo doors and main deck side cargo doors was reinstalled in accordance with paragraph (g)(2)(ii) of this AD, replace those cam latches with cam latches of the new part configuration, in accordance with Section III. of the service bulletin. Prior to further flight, perform an operational test of the door latch mechanism in accordance with Section III., paragraph Y., of the service bulletin. \n\n\tNOTE: Accomplishment of the requirements of paragraphs (g) and (h) of this AD in accordance with Boeing Alert Service Bulletin 747-52A2233, dated August 29, 1991, as amended by Notice of Status Change 747-52A2233 NSC 1, dated November 21, 1991; is equivalent to accomplishment of those requirements in accordance with Boeing Alert Service Bulletin 747-52A2233, dated August 29, 1991.\n\n\t(i)\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 Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. 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 \n\tNOTE: 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(j)\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. \n\n\t(k)\tThe inspections, replacements, check, repairs, installation, operational tests, and sealant application shall be done in accordance with the following Boeing service bulletins, as applicable, which contain the specified effective pages: \n\n\nService Bulletin\tReferenced and Date\n\nPage Number\t\nRevision Level\tShown on Page\n Date \nShown on Page \n747-52-2186,\nRevision 4, \nOctober 24, 1991\n1-15, 19-50\t\n\n16-18\t\n4\n\n3\nOctober 24, 1991\n\nJanuary 25, 1990 \n747-52A2233,\nAugust 29, 1991\n1-76\nOriginal\nAugust 29, 1991\nNotice of Status Change\n747-52A2233 NSC 1\nNovember 21, 1991 \n1\n2\nOriginal\n(This page is not dated) \nNovember 21, 1991 \n\nThis incorporation by reference was approved previously by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51, as of May 14, 1993 (58 FR 19322, April 14, 1993). 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(l)\tThis amendment is effective May 14, 1993.
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