AD 2004-09-10 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, certificated in any category, with lower cargo floors (floors in the lower cargo areas) that are not fully enclosed. A fully enclosed cargo floor is a floor with panels installed between all roller trays in the cargo compartment. A cargo floor that is not fully enclosed is a floor without panels installed between all roller trays in the cargo compartment.

Required as indicated, unless accomplished previously. To prevent overheating of the heater tape on potable water fill and drain lines, which may ignite accumulated debris or contaminants on or near the potable water fill and drain lines, resulting in a fire in the airplane, accomplish the following: Debris Removal (a) At the later of the times specified in paragraphs (a)(1) and (a)(2) of this AD: Perform a one-time general visual inspection for foreign object debris (FOD) and contamination on or near potable water and drain lines located below the cargo floor in the forward and aft cargo compartments, in areas not covered by floor panels or sidewall panels. Do the inspection in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-30A2079, Revision 1, dated October 16, 2003. Remove any FOD or contamination observed on or near the potable water or drain lines prior to further flight in accordance with the service bulletin. (1) Inspect within 18 months since the date of issuance of the original Airworthiness Certificate or within 18 months since the date of issuance of the Export Certificate of Airworthiness, whichever occurs first; or (2) Inspect within 90 days after the effective date of this AD. Note 1: For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.” Inspection for Discrepant Heater Tape (b) At the applicable time specified in paragraph (c) of this AD: Perform a general visual inspection for discrepancies of potable water and drain lines located below the cargo floor in the forward and aft cargo compartments, in areas not covered by floor panels or sidewall panels, as specified in paragraphs (b)(1) and (b)(2) of this AD. Do the inspection in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-30A2079, Revision 1, dated October 16, 2003. (1) Inspect potable water and drain lines for indications of overheating of the heater tape, including localized darkening of foam insulation or protective tape. If overheating is observed: Prior to further flight, either replace the defective heater tape, removing floor panels as necessary, in accordance with the service bulletin; deactivate the heater tape in accordance with the provisions and limitations specified in the operator's Minimum Equipment List (MEL); or deactivate the heater tape in accordance with Figure 1 of the service bulletin. If the heater tape is deactivated it must be replaced within 90 days after the date of the inspection required by this paragraph. (2) Inspect potable water and drain lines for exposed foam insulation and missing or damaged protective tape. If exposed foam insulation is observed: Within 90 days after the date of the inspection required by this paragraph, cover the foam insulation with a continuous wrap of protective tape, in accordance with the service bulletin. If protective tape is missing or damaged: Within 90 days after the date of the inspection required by this paragraph, replace the protective tape in accessible areas in accordance with the service bulletin. It is not necessary to remove floor panels to replace the protective tape. (c) Do the inspections required by paragraph (b) at the later of the times specified in paragraphs (c)(1) and (c)(2) of this AD. (1) Within 18 months since the date of issuance of the original Airworthiness Certificate or the date of issuance of the Export Certificate of Airworthiness, whichever occurs first. (2) Within 90 days after the effective date of this AD. Credit for Actions Accomplished Previously (d) Actions accomplished before the effective date of this AD, per Boeing Alert Service Bulletin 747-30A2079, dated December 12, 2002, are acceptable for compliance with the corresponding actions required by paragraphs (a) and (b) of this AD. 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 Aircraft Certification Office (ACO), FAA. 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. Incorporation by Reference (f) Unless otherwise specified in this AD, the actions shall be done in accordance with Boeing Service Bulletin 747-30A2079, Revision 1, dated October 16, 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, PO 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 (g) This amendment becomes effective on June 4, 2004. Issued in Renton, Washington, on April 20, 2004. Ali Bahrami, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 04-9592 Filed 4-29-04; 8:45 am] BILLING CODE 4910-13-U