99-10-16: Manhole Doublers

99-10-16 MITSUBISHI HEAVY INDUSTRIES, LTD.: Amendment 39-11169. Docket 97-NM-92-AD. Applicability: All Model YS-11 series airplanes, certificated in any category. NOTE 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 (c) 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. Compliance: Required as indicated, unless accomplished previously. To prevent fatigue cracking in the manhole doublers of the lower wing panels, which could result in failure of the wing structure, accomplish the following: Initial and Repetitive Inspections (a) Perform a visual inspection to detect cracking in the manhole doublers and around the screw holes of the lower wing panels, in accordance with Mitsubishi Nihon Aeroplane Manufacturing Company (NAMC) Service Bulletin 57-77, Revision 2, dated September 14, 1994, at the time specified in either paragraph (a)(1) or (a)(2) of this AD, as applicable. Repeat the inspection thereafter at intervals not to exceed 6,000 flight cycles. (1) For airplanes that have accumulated fewer than 45,000 total flight cycles as of the effective date of this AD: Prior to the accumulation of 45,000 total flight cycles, or within 1 year after the effective date of this AD, whichever occurs later, perform the initial inspection. (2) For airplanes that have accumulated 45,000 or more total flight cycles as of the effective date of this AD: Within 2,000 flight cycles or 1 year after the effective date of this AD, whichever occurs first, perform the initial inspection. Modification (b) Modify the screw holes in the manhole doublers of the lower wing panels, in accordance with Mitsubishi NAMC Service Bulletin 57-77, Revision 2, dated September 14, 1994, at the applicable time specified in either paragraph (b)(1) or (b)(2) of this AD. Accomplishment of such modification constitutes terminating action for the repetitive inspections required by paragraph (a) of this AD. NOTE 2: Mitsubishi NAMC Supplemental Inspection Document (SID) Item 57-00-03 describes inspections of certain rivet holes in the skin around the manhole. Accomplishment of the modification specified in paragraph (b) of this AD does not eliminate the need for the inspections specified in that SID item. (1) If no cracking is found, prior to the accumulation of 60,000 total flight cycles, or within 1 year after the effective date of this AD, whichever occurs later, accomplish the modification in accordance with the service bulletin. (2) If any cracking is found, prior to further flight, repair the cracking and accomplish the modification, in accordance with the service bulletin. Alternative Methods of Compliance (c) An 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, Los Angeles 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, Los Angeles ACO. NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. Special Flight Permits (d) Special 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. Incorporation by Reference (e) The inspection and modification shall be done in accordance with Mitsubishi Nihon Aeroplane Manufacturing Company (NAMC) Service Bulletin 57-77, Revision 2, dated September 14, 1994, which contains the following list of effective pages: Page Number Revision Level Shown on Page Date Shown on Page 1-3 2 September 14, 1994 4-16 1 November 4, 1993 17, 18 Original January 8, 1993 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 Mitsubishi Heavy Industries, Ltd., 10 Oye-cho, Minato-ku, Nagoya 455, Japan. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. NOTE 4: The subject of this AD is addressed in Japanese airworthiness directive TCD-3795-2-96, dated December 13, 1996. (f) This amendment becomes effective on June 22, 1999. FOR FURTHER INFORMATION CONTACT: Jon Mowery, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5322; fax (562) 627-5210.