AD 90-13-05

90-13-05 BOEING: Amendment 39-6617. Docket No. 89-NM-272-AD.

Applicability: Model 747 series airplanes listed in Boeing Alert Service Bulletin 747- 35A2061, dated October 19, 1989, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To ensure that sufficient oxygen is available to supernumerary during emergency conditions, accomplish the following:

A. Within the next 10 days after the effective date of this AD, revise the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) to include the following statement. This may be accomplished by inserting a copy of this AD in the AFM. "Limit occupancy of supernumeraries to 16 people."

B. Within the next 3,000 hours time-in-service after the effective date of this AD, remove and replace the bleed relief valves with higher operating pressure bleed relief valves, in accordance with Boeing Alert Service Bulletin 747-35A2061, dated October 19, 1989. Once this is accomplished, the limitation required by paragraph A., above may be removed from the AFM.

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, FAA, Northwest Mountain Region.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment, and then send it to the Manager, Seattle Aircraft Certification Office.

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 Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington.

This amendment (39-6617, AD 90-13-05) becomes effective on July 23, 1990.