AD 2002-18-04 Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SP, and 747SR Series Airplanes

Models named: 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SP, 747SR series. Read the applicability below — it usually turns on serial or part numbers too.

Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SP, and 747SR series airplanes; line numbers 1 through 810 inclusive; certificated in any category; and NOT equipped with a nose cargo door. 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 (e) 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.

Required as indicated, unless accomplished previously. To find and fix cracking in certain upper deck floor beams, which could extend and sever floor beams adjacent to the body frame and result in rapid depressurization of the airplane, accomplish the following: Inspections (a) At the compliance time specified in paragraph (a)(1) or (a)(2) of this AD, as applicable, perform one-time detailed and open-hole high frequency eddy current (HFEC) inspections for cracking in the upper deck floor beams at station (STA) 340 and STA 360, according to Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001. For the purposes of this AD, flight cycles with a cabin differential pressure of 2.0 psi or less are not calculated into the compliance thresholds specified in this AD. However, all cabin pressure records must be maintained for each airplane, and no fleet averaging of cabin pressure is allowed. Note 2: For the purposes of this AD, a detailed 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.” (1) For airplanes with 22,000 or fewer total flight cycles as of the effective date of this AD: Do the inspections prior to the accumulation of 16,000 total flight cycles, or within 1,500 flight cycles after the effective date of this AD, whichever is later. (2) For airplanes with more than 22,000 total flight cycles as of the effective date of this AD: Do the inspections within 500 flight cycles after the effective date of this AD. Modification (b) If no crack is found during the inspections per paragraph (a) of this AD: Within 5,000 flight cycles after the initial inspections, modify the upper deck floor beams at STA 340 and STA 360, according to Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001. If this modification is not accomplished before further flight after the inspections required by paragraph (a) of this AD, those inspections must be repeated one time, immediately before accomplishing the modification in this paragraph. If any crack is found during these repeat inspections, before further flight, accomplish paragraph (c)(2) of this AD. Repair (c) If any crack is found during the inspections per paragraph (a) of this AD: Before further flight, repair according to either paragraph (c)(1) or (c)(2) of this AD. (1) Accomplish repairs according to paragraphs (c)(1)(i) and (c)(1)(ii) of this AD. (i) Accomplish a time-limited repair (including removing certain fasteners and the existing strap, performing open-hole HFEC inspections of the chord and web, stop-drilling web cracks, replacing the outboard section of the web, if applicable, and installing new straps) according to Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001; except where the service bulletin specifies to contact Boeing for appropriate action, repair according to a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or according to data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative (DER) who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved as required by this paragraph, the approval must specifically reference this AD. AND (ii) Within 18 months or 1,500 flight cycles after installation of the time-limited repair according to paragraph (c)(1)(i) of this AD, whichever is first, do paragraph (c)(2) of this AD. (2) Accomplish a permanent repair according to Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001; except where the service bulletin specifies to contact Boeing for appropriate action, repair according to a method approved by the Manager, Seattle ACO; or according to data meeting the type certification basis of the airplane approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved as required by this paragraph, the approval must specifically reference this AD. Repetitive Inspections: Post-Modification/Repair (d) Within 15,000 flight cycles after modification of the upper deck floor beams per paragraph (b) of this AD, or permanent repair of the upper deck floor beams per paragraph (c) of this AD, as applicable: Perform either open-hole HFEC inspections for cracking of fastener holes common to the upper chord, reinforcement straps, and the body frame; or surface HFEC inspections for cracking along the lower edge of the upper chord of the floor beam at the intersection with the body frame; and repeat these inspections at the interval specified in paragraph (d)(1) or (d)(2) of this AD, as applicable. Perform these inspections and repair any cracking found during these inspections according to a method approved by the Manager, Seattle ACO, or according to data meeting the type certification basis of the airplane approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make such findings. For an inspection or repair method to be approved as required by this paragraph, the approval must specifically reference this AD. (1) If the most recent inspection used the surface HFEC method: Repeat the inspection within 1,000 flight cycles. (2) If the most recent inspection used the open-hole HFEC method: Repeat the inspection every 3,000 flight cycles. Note 3: There is no terminating action at this time for the repetitive post-modification/repair inspections according to paragraph (d) of this AD, and instructions for these inspections are not provided in Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001. Alternative Methods of Compliance (e) 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, 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. Note 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. Special Flight Permits (f) 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 (g) Except as provided by paragraphs (c)(1)(i), (c)(2), and (d) of this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001. 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. Effective Date (h) This amendment becomes effective on October 16, 2002. Issued in Renton, Washington, on August 30, 2002. Ali Bahrami, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 02-22855 Filed 9-10-02; 8:45 am] BILLING CODE 4910-13-P