99-23-13: Forward and Aft Frame Inspection

99-23-13 BOEING: Amendment 39-11409. Docket 97-NM-227-AD.\n\n\tApplicability: All Model 727-200 series airplanes, 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 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 (d) 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 detect and correct fatigue cracking between the upper and lower sills of the number 1 cargo door, which could result in rapid decompression of the fuselage and consequent reduced structural integrity of the airplane, accomplish the following: \n\nInitial Inspection \n\n\t(a)\tPerform a detailed visual inspection or a high frequency eddy current (HFEC) inspection (as applicable) to detect cracks in the forward and aft frames (web, inner chord, and outer chord), bear strap, and fuselage skin between the upper and lower sills of the number 1 cargo door at BS 560 and BS 620. Accomplish the inspection at the time specified in paragraph (a)(1), (a)(2), or (a)(3) of this AD, as applicable. \n\n\tNOTE 2: For the purposes of this AD, a detailed visual inspection is defined as: "An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required." \n\n\t\t(1)\tFor any forward or aft frame (web, inner chord, and outer chord), bear strap, or fuselage skin that has not been repaired in accordance with Boeing Service Bulletin 727-53A0219, Revision 1, dated May 8, 1997: Inspect prior to the accumulation of 30,000 total flight cycles, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later, in accordance with the Accomplishment Instructions of the service bulletin. \n\n\t\t(2)\tFor any forward or aft frame (web, inner chord, and outer chord) that has been repaired in accordance with Boeing Service Bulletin 727-53A0219, Revision 1, dated May 8, 1997: Inspect within 3,000 flight cycles after the effective date of this AD, in accordance with the Accomplishment Instructions of the service bulletin. \n\n\t\t(3)\tFor any bear strap, fuselage skin, or a combination of the frame web and chord (inner or outer) on either the forward or aft frame that has been repaired in accordance with Boeing Service Bulletin 727-53A0219, Revision 1, dated May 8, 1997: Inspect within 3,000 flight cycles after the effective date of this AD, in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. \n\n\tNOTE 3: Where there are differences between this AD and the referenced service bulletin, the AD prevails. \n\n\tNOTE 4: The inspections specified in paragraph (a)(3) of this AD are not defined in the service bulletin. \n\nRepetitive Inspections \n\n\t(b)\tIf no crack is detected during any inspection required by paragraph (a) of this AD, accomplish paragraph (b)(1) or (b)(2) of this AD, as applicable. \n\n\t\t(1)\tFor any forward or aft frame (web, inner chord, and outer chord), bear strap, or fuselage skin identified in paragraphs (a)(1) and (a)(2) of this AD: Repeat the detailed visual and HFEC inspections required by paragraph (a) of this AD thereafter at the times specified in paragraphs (b)(1)(i) and (b)(1)(ii) of this AD. \n\n\t\t\t(i)\tRepeat the detailed visual inspection of the frame web at intervals not to exceed 3,000 flight cycles. \n\n\t\t\t(ii)\tRepeat the detailed visual and HFEC inspections (as applicable) of the frame web, frame inner and outer chords, bear strap, and fuselage skin thereafter at intervals not to exceed 15,000 flight cycles. \n\n\t\t(2)\tFor any bear strap, fuselage skin, or a combination of the frame web and chord (inner or outer) on either the forward or aft frame identified in paragraph (a)(3) of this AD: Repeat the inspections of the repaired bear strap, fuselage skin, or combination of a repaired frame web and chord (inner or outer) thereafter at intervals not to exceed those approved by the Manager, Seattle ACO. \n\nRepair \n\n\t(c)\tIf any crack is detected during any inspection required by paragraph (a) of this AD, prior to further flight, accomplish paragraph (c)(1) or (c)(2) of this AD, as applicable. \n\n\t\t(1)\tFor any crack detected in the frame web, inner chord, or outer chord: Repair in accordance with Boeing Service Bulletin 727-53A0219, Revision 1, dated May 8, 1997. Prior to the accumulation of 3,000 flight cycles after accomplishment of the repair, accomplish the detailed visual and HFEC inspections specified in paragraph (a) of this AD. Repeat the detailed visual inspection of the frame web thereafter at intervals not to exceed 3,000 flight cycles. Repeat the detailed visual and HFEC inspections (as applicable) of the frame web, inner chord, and outer chord thereafter at intervals not to exceed 15,000 flight cycles. \n\n\t\t(2)\tFor any crack detected in the fuselage skin, bear strap, or a combination of the frame web and chord (inner or outer): Repair and perform repetitive inspections in accordance with both a method and repetitive inspection interval approved by the Manager, Seattle ACO.\n\n\tNOTE 5: Therepairs and inspections specified in paragraph (c)(2) of this AD are not defined in the service bulletin. \n\nAlternative Methods of Compliance \n\n\t(d)\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\n\tNOTE 6: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\nSpecial Flight Permits \n\n\t(e)\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\nIncorporation by Reference\n \n\t(f)\tExcept as provided by paragraphs (a)(3), (b)(2), and (c)(2) of this AD, the actions shall be done in accordance with Boeing Service Bulletin 727-53A0219, Revision 1, dated May 8, 1997. 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(g)\tThis amendment becomes effective on December 17, 1999.