AD 88-21-03 R1

88-21-03 R1 AIRBUS INDUSTRIE AND BOEING: Amendment 39-6045 as amended by Amendment 39-6077. Applies to all Airbus Model A300 and A310-200 series airplanes, and Boeing Models 737-200, 737-300, 757-200, 767-200, and 767-300 series airplanes, certificated in any category, which are approved for operations over a route that contains a point farther than one hour flying time at the normal one-engine inoperative cruise speed (in still air) from an adequate airport in deviation from Section 121.161 of the Federal Aviation Regulations, referred to as "extended range," "EROP," or "ETOP" operations. Compliance required within 30 days after the effective date of the AD, unless previously accomplished.

To prevent failure of the fuel crossfeed valve during a single engine diversion on an extended range flight, which could result in the inability of the airplane to stay within the airplane lateral imbalance limit or in fuel starvation in the operating engine before the airplane is ableto reach the diversion airport, accomplish the following:

A. Revise the LIMITATIONS SECTION of the FAA-approved Airplane Flight Manual (AFM) or Flight Manual Appendix, as appropriate, by adding the following instructions. This may be accomplished by inserting a copy of this AD in the AFM.

Fuel Crossfeed Valve.

Perform an operational check of the fuel crossfeed valve during the last hour of cruise flight during each extended range operation. Enter valve failure conditions resulting from the operational check in the airplane log.

B. Repair or replace, prior to next flight, any fuel crossfeed valve system component not exhibiting proper operation.

C. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety and which has the concurrence of an FAA Principal Operations Inspector, 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 Operations Inspector (POI), who may add any comments and then send it to the Manager, Seattle Aircraft Certification Office.

This amendment revises AD 88-21-03, Amendment 39-6045, effective October 24, 1988. This amendment, 39-6077, becomes effective November 18, 1988.