AD 98-16-13 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, line positions 1 through 1157; 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 prevent accelerated fatigue cracking of the inner chords of the Body Station (BS) 2598 bulkhead, which could result in inability of the structure to carry horizontal stabilizer flight loads, and consequent reduced controllability of the airplane; accomplish the following: (a) Prior to the accumulation of 8,000 total flight cycles, or within 90 days after the effective date of this AD, whichever occurs later, perform a one-time visual inspection for missing fasteners of the splice fitting of the forward inner chord of the BS 2598 bulkhead, on the left and right sides of the airplane, in accordance with Boeing Alert Service Bulletin 747-53A2423, dated June 11, 1998. (1) If all fasteners are present, no further action is required by this AD. (2) If any fastener is missing, prior to further flight, accomplish a detailed visual inspection and a high frequency eddy current inspection to detect cracking of the forward and aft inner chords of the BS 2598 bulkhead, on the left and right sides of the airplane; in accordance with the alert service bulletin. (i) If no cracking is detected, prior to further flight, install the fasteners, in accordance with the alert service bulletin. (ii) If any cracking is detected, prior to further flight, repair the cracking and install the fasteners, in accordance with Boeing 747 Structural Repair Manual (SRM) 53-10-04, Figure 72, or Boeing 747SP SRM 53-19-02, Figure 41; as applicable; or repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. (b) Within 10 days after accomplishing the inspection required by paragraph (a) of this AD, submit a report of the inspection results (findings of missing fasteners only) to the Manager, Seattle Manufacturing Inspection District Office, FAA, Transport Airplane Directorate, 2500 East Valley Road, suite C-2, Renton, Washington 98055-4056; fax (425) 227-1181. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056. (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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. (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. (e) Except as provided by paragraph (a)(2)(ii) of this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin 747-53A2423, dated June 11, 1998. 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. (f) This amendment becomes effective on August 18, 1998. Issued in Renton, Washington, on July 27, 1998. S.R. Miller, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-20679 Filed 7-31-98; 8:45 am] BILLING CODE 4910-13-U