95-12-24: Structural Integrity of Fuselage

95-12-24 LOCKHEED AERONAUTICAL SYSTEMS COMPANY: Amendment 39-9277. Docket 95-NM-103-AD. Applicability: All Model L-1011-385 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 use the authority provided in paragraph (f) of this AD to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD. Compliance: Required as indicated, unless accomplished previously. To prevent reduced structural integrity of the fuselage due to fatigue cracking of the pressure bulkhead, accomplish the following: (a) Prior to the accumulation of 18,000 total landings, or within 30 days after the effective date of this AD, whichever occurs later, perform a visual inspection to detect cracking of the bulkhead at fuselage station (FS) 1363 in the area of the stiffeners at left and right butt line (BL) 42.5, in accordance with the procedures specified in paragraphs 2.A. and 2.B. of the Accomplishment Instructions of Lockheed L-1011 Service Bulletin 093-53-268, dated April 15, 1993. NOTE 2: This AD does not require that the eddy current inspection referenced in paragraph 2.B. of the Accomplishment Instructions of Lockheed L-1011 Service Bulletin 093-53-268, dated April 15, 1993, be accomplishedas a requirement of paragraph (a) of this AD. (b) If no cracking of the bulkhead is detected, no further action is required by this AD. (c) Except as provided by paragraph (e) of this AD, if any cracking of the bulkhead is detected below waterline (WL) 117: Prior to further flight, perform the inspections required by paragraphs (c)(1), (c)(2), and (c)(3) of this AD, in accordance with LCC-7622-373, dated May 9, 1995. Prior to further flight, repair any cracking of the frame cap found during these inspections, in accordance with Lockheed document LCC-7622-374, dated May 9, 1995. (1) Perform a bolt hole eddy current inspection to detect cracking of the eight fastener holes at the intersection of the vertical stiffener at BL 42.5 and the frame cap vertical flange; and (2) Perform a bolt hole eddy current inspection to detect cracking at eight fastener locations in the frame cap lower flange that connect the lower fuselage skin panel to the frame at the BL 42.5 vertical stiffener; and (3) Perform a visual inspection to detect stress corrosion cracking of the accessible portions of the fillet radius of the frame cap. (d) Except as provided by paragraph (e) of this AD, if any cracking of the bulkhead is detected at or above WL 117: Prior to further flight, repair the bulkhead cracking in accordance with the procedures specified in Part II of the Accomplishment Instructions of Lockheed L-1011 Service Bulletin 093-53-268, dated April 15, 1993. (e) Continued flight with cracking of the bulkhead is permitted, provided that the conditions specified in paragraph 1.C. of the Planning Information of Lockheed L-1011 Service Bulletin 093-53-268, dated April 15, 1993, are met. For flight with cracking, both the visual and eddy current inspections specified in paragraphs 2.B. and 2.C. of the Accomplishment Instructions of the service bulletin must be accomplished prior to returning the aircraft to service. These visual and eddy current inspectionsmust be repeated within 900 landings. Prior to the accumulation of 1,800 total landings, these inspections must be terminated by the installation of the repair specified in Part II of the Accomplishment Instructions of the service bulletin. (f) 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, Atlanta Aircraft Certification Office (ACO), FAA, Small 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, Atlanta ACO. NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO. (g) 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 locationwhere the requirements of this AD can be accomplished. (h) The inspections and repair shall be done in accordance with Lockheed L-1011 Service Bulletin 093-53-268, dated April 15, 1993; Lockheed document LCC-7622-373, dated May 9, 1995; and Lockheed document LCC-7622-374, dated May 9, 1995. 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 Lockheed Aeronautical Systems Support Company (LASSC), Field Support Department, Dept. 693, Zone 0755, 2251 Lake Park Drive, Smyrna, Georgia 30080. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Atlanta Aircraft Certification Office, Small Airplane Directorate, Campus Building, 1701 Columbia Avenue, Suite 2-160, College Park, Georgia; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (i) This amendment becomes effective on July 3, 1995.