AD 91-09-06

91-09-06 BOEING: Amendment 39-6977. Docket No. 90-NM-216-AD.

Applicability: Model 727 series airplanes equipped with forward and/or aft auxiliary fuel tank listed in Boeing Alert Service Bulletin 727-28A0067, Revision 1, dated July 5, 1990, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To eliminate the potential for a fire due to rupture of the auxiliary fuel tanks, accomplish the following:

A. Within the next 18 months after the effective date of this AD, accomplish either subparagraph A.1. or A.2., below:

1. Install a check valve and a pressure actuated shutoff valve in the center wing tank in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 727-28A0067, Revision 1, dated July 5, 1990.

2. Deactivate the auxiliary fuel system and insert a placard in the cockpit to indicate that the auxiliary fuel tank is inoperative, in accordance with Boeing Service Alert Bulletin727-28A0067, Revision 1, dated July 5, 1990.

B. 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.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Seattle ACO.

C. 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 Airplane 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 SW., Renton, Washington.

This amendment (39-6977, 91-09-06) becomes effective on May 28, 1991.