AD 90-20-22

90-20-22 BOEING: Amendment 39-6728. Docket No. 90-NM-44-AD.

Applicability: Model 737 series airplanes, as listed in Alert Service Bulletin 737- 57A1197, dated December 21, 1989, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent fuel vapor leaks into the inboard fixed leading edge landing light cavities, resulting in fuel vapor ignition, accomplish the following:

A. Within the next 180 days after the effective date of this AD, inspect the wings' inboard leading edge landing and runway turn-off/taxi light cavities for improper fuel vapor barrier sealing, in accordance with Boeing Alert Service Bulletin 737-57A1197, dated December 21, 1989. If the sealing is found to be improperly applied, rework the vapor barrier sealing prior to further flight, in accordance with the service bulletin.

B. Within 10 days after the inspection required by paragraph A. of this AD, if configuration discrepancies are discovered, submit a report of findings to the Manager, Seattle Manufacturing District Office, FAA, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington 98055-4056.

C. An alternate means 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.

NOTE: The request should be submitted directly to the Manager, Seattle ACO, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Seattle ACO.

D. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Boeing CommercialAirplane Group, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington 98055-4056.

This amendment (39-6728, AD 90-20-22) becomes effective on October 23, 1990.