AD 92-04-07

92-04-07 BOEING: Amendment 39-8178. Docket 92-NM-16-AD.

Applicability: All Model 737-300, 737-400, and 737-500 series airplanes, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent the occurrence of fire and smoke in the passenger cabin and cockpit, accomplish the following:

(a) Within 20 days after the effective date of this AD, visually inspect the wire bundles above the cockpit-to-cabin door header frame for damage due to chafing or interference with the door header frame. Pay particular attention to the wire bundle crossing over the right- hand corner of the header frame. Proper inspection requires removal of the aft center ceiling panel located just forward of the cockpit-to-cabin door. Ensure that the wire bundle clamps above the cockpit-to-cabin door header frame located approximately at Station 282.5, stringers 2R and 2L, are connected securely to stringer clip standoffs. (These should not befree floating clamps.) If any damaged wire bundle or loose clamp is found, prior to further flight, repair and/or secure it, in accordance with Boeing Standard Wiring Practices Document.

(b) Repeat the inspection procedure required by paragraph (a) of this AD at intervals not to exceed 120 days.

(c) Within 30 days after the effective date of this AD, sleeve the wire bundles in the area where they cross the cockpit-to-cabin door header frame with Expando PT or equivalent protective sleeving. Ensure that there is a minimum of 0.25 inch of clearance between these bundles and the cockpit-to-cabin door frame header, to prevent chafing or interference. If rework is necessary, perform it prior to further flight, in accordance with Boeing Standard Wiring Practices Document.

(d) An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office(ACO), FAA, Transport Airplane Directorate. The request shall be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Seattle Aircraft Certification Office (ACO).

(e) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(f) This amendment (39-8178, AD 92-04-07) becomes effective on February 21, 1992.