AD 2004-09-33 Airworthiness Directives; Boeing Model 747-400 and 747-400D Series Airplanes

Models named: 747-400, 747-400D series. Read the applicability below — it usually turns on serial or part numbers too.

Model 747-400 and 747-400D series airplanes, as listed in Boeing Service Bulletin 747-26A2270, Revision 2, dated June 26, 2003; certificated in any category.

Required as indicated, unless accomplished previously. To prevent a chafed hole in the fire extinguishing system tube of the aft cargo compartment, which could result in a lack of fire extinguishing agent and consequent uncontained fire in the aft cargo compartment, accomplish the following: Service Bulletin References (a) The term “service bulletin,” as used in this AD, means the Accomplishment Instructions of Boeing Service Bulletin 747-26A2270, Revision 2, dated June 26, 2003. Inspection/Pressure Test (b) Within 6,500 flight hours or 18 months after the effective date of this AD, whichever occurs first, perform the detailed inspection specified in paragraph (b)(1) of this AD or the pressure test specified in paragraph (b)(2) of this AD. Note 1: 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) Perform a detailed inspection of the fire extinguishing system tube and clamps for correct installation, either using an inspection hole and boroscope or with the floor panel removed, per the service bulletin. (i) If the fire extinguishing system tube is installed correctly, no further action is required by this AD. (ii) If the fire extinguishing system tube is installed incorrectly, prior to further flight, do the actions specified in paragraph (c) of this AD. (2) Perform a pressure test of the fire extinguishing system tube to check for leakage of the fire extinguishing agent per the service bulletin. (i) If leakage is not found, repeat the pressure test thereafter at intervals not to exceed 6,500 flight hours or 18 months, whichever occurs first, until the actions specified in paragraph (b)(1) or (c) of this AD have been done. (ii) If any leakage is found, prior to further flight, do the actions specified in paragraph (c) of this AD. Removal and Installation/Repair/Replace (c) Remove the fire extinguishing system tube and do the actions in paragraph (c)(1) or (c)(2) of this AD, as applicable. (1) If, during the detailed inspection specified in paragraph (b)(1) of this AD, the fire extinguishing system tube was found to be installed incorrectly: Prior to further flight, perform a detailed inspection of the fire extinguishing system tube for chafing/damage per the service bulletin. (i) If no chafing/damage is found, prior to further flight, install the existing fire extinguishing system tube per Figure 3 of the service bulletin. (ii) If any chafing/damage is found, prior to further flight, replace the fire extinguishing system tube with a new tube or repair the fire extinguishing system tube, per the service bulletin, and install the new or repaired tube per Figure 3 of the service bulletin. (2) If, during the pressure test required by paragraph (b)(2) of this AD, leakage was found: Prior to further flight, replace the fire extinguishing system tube with a new tube or repair the fire extinguishing system tube, per the service bulletin, and install the new or repaired tube per Figure 3 of the service bulletin. Terminating Action (d) Accomplishment of the actions specified in paragraph (b)(1) or (c) of this AD constitutes terminating action for the requirements of this AD. Actions Accomplished Per Previous Issue of Service Bulletin (e) Inspections, repetitive tests and corrective actions accomplished before the effective date of this AD per Boeing Alert Service Bulletin 747-26A2270, dated May 8, 2002; or Revision 1, dated January 16, 2003; are considered acceptable for compliance with the corresponding action specified in this AD. Alternative Methods of Compliance (f) In accordance with 14 CFR 39.19, the Manager, Seattle Aircraft Certification Office, FAA, is authorized to approve alternative methods of compliance (AMOCs) for this AD. Incorporation by Reference (g) Unless otherwise specified in this AD, the actions shall be done in accordance with Boeing Service Bulletin 747-26A2270, Revision 2, dated June 26, 2003. 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 Airplanes, 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 National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/ federal_register/ code_of_ federal_ regulations/ibr_ locations.html . Effective Date (h) This amendment becomes effective on June 15, 2004. Issued in Renton, Washington, on April 23, 2004. Kalene C. Yanamura, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 04-10251 Filed 5-10-04; 8:45 am] BILLING CODE 4910-13-P