AD 2001-14-07 Airworthiness Directives; Boeing Model 747 Series Airplanes

Models named: 747 series. Read the applicability below — it usually turns on serial or part numbers too.

Model 747 series airplanes, as listed in Boeing Service Bulletin 747-53A2449, Revision 1, dated May 24, 2001, 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.

Required as indicated, unless accomplished previously. To find and fix fatigue cracking in the bulkhead frame support at body station (BS) 2598 under the hinge support fittings of the horizontal stabilizer, which could result in inability of the structure to carry horizontal stabilizer flight loads and reduced controllability of the horizontal stabilizer, accomplish the following: Repetitive High Frequency Eddy Current (HFEC) Inspections (a) Before the accumulation of 10,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later: Do an open-hole HFEC inspection to find cracking of the bulkhead frame support under the hinge support fittings of the horizontal stabilizer on the left and right sides at BS 2598, per Figure 2 of the Accomplishment Instructions of Boeing Service Bulletin 747-53A2449, Revision 1, dated May 24, 2001. Repeat the inspection after that at intervals not to exceed 3,000 flight cycles. Note 2: Inspections accomplished before the effective date of this AD per Boeing Alert Service Bulletin 747-53A2449, dated June 8, 2000, are considered acceptable for compliance with the applicable inspection specified in paragraph (a) of this AD. Repair (b) If any cracking is found during any inspection required by paragraph (a) of this AD, before further flight, repair per a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the approval letter must specifically reference this AD. 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, 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 3: 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 (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) Except as provided by paragraph (b) of this AD, the actions shall be done per Boeing Service Bulletin 747-53A2449, Revision 1, dated May 24, 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 (f) This amendment becomes effective on August 16, 2001. Issued in Renton, Washington, on July 2, 2001. Vi L. Lipski, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 01-17119 Filed 7-11-01; 8:45 am] BILLING CODE 4910-13-U