AD 2001-24-29 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 Alert Service Bulletin 747-35A2035, Revision 1, dated July 22, 1999; 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 (b) 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 chafing between the oxygen hose and electrical wire bundles at certain passenger service units, which could result in arcing of a chafed wire bundle and consequent burn-through of the oxygen hose, with the arcing potentially representing an ignition source in an oxygen-enriched environment, accomplish the following: Inspection and Follow-On Actions (a) Within 18 months after the effective date of this AD, do a detailed visual inspection for chafing between oxygen hoses and electrical wire bundles at the passenger service units (PSU) in the main deck passenger compartment, upper deck sculpted ceiling, personnel accommodation (crew rest) area, lower lobe forward galley, and aft galley; as applicable. Do the inspection according to Boeing Alert Service Bulletin 747-35A2035, Revision 1, dated July 22, 1999, as revised by Boeing Service Bulletin Information Notice 747-35A2035 IN 01, dated September 23, 1999. Before further flight following this inspection, do the corrective actions in paragraphs (a)(1) and (a)(2) of this AD, as applicable, and reroute the oxygen hose or install an elbow at the oxygen mask inlet connector to reorient the oxygen hose away from the electrical wiring, as applicable, to ensure a minimum of 2 inches clearance between the oxygen hose and electrical wire bundle, according to the service bulletin. Note 2: For the purposes of this AD, a detailed visual 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) If any chafing of an oxygen hose is found: Replace the chafed oxygen hose with a new oxygen hose, and install protective sleeving over the new oxygen hose, according to the service bulletin. (2) If any chafing of a wire bundle is found, repair the wire bundle according to the service bulletin. Note 3: Inspections and follow-on actions done prior to the effective date of this AD according to Boeing Service Bulletin 747-35-2035, dated January 7, 1983, are acceptable for compliance with corresponding actions in paragraph (a) of this AD. Alternative Methods of Compliance (b) 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 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 (c) 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 (d) The actions shall be done in accordance with Boeing Alert Service Bulletin 747-35A2035, Revision 1, dated July 22, 1999, as revised by Boeing Service Bulletin Information Notice 747-35A2035 IN 01, dated September 23, 1999. 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 (e) This amendment becomes effective on January 16, 2002. Issued in Renton, Washington, on November 28, 2001. Vi L. Lipski, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 01-30205 Filed 12-11-01; 8:45 am] BILLING CODE 4910-13-P