AD 89-07-08

89-07-08 McDONNELL DOUGLAS: Amendment 39-6177.

Applicability: Model DC-9 and C-9 (Military) series airplanes, Fuselage 1 through 895, as listed in McDonnell Douglas DC-9 Service Bulletin 24-57, Revision 1, dated March 12, 1980, certificated in any category.

Compliance: Required within 60 days after the effective date of this AD, unless previously accomplished.

To prevent the AC cross tie relay from shorting out internally and causing total loss of AC electrical power and to eliminate a potential source of fire ignition, accomplish the following:

A. Install current limiters in the aircraft wiring at the AC cross tie relay in accordance with the accomplishment instructions of McDonnell Douglas DC-9 Service Bulletin 24-57, Revision 1, dated March 12, 1980.

B. 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, Los Angeles Aircraft Certification Office,FAA, Northwest Mountain Region.

NOTE: The request should be forwarded through an FAA Principal Avionics Inspector (PAI), who may add any comments and then send it to the Manager, Los Angeles Aircraft Certification Office.

C. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes unpressurized 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 McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Director of Publications, C1-LOO (54-60). These documents may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or 3229 East Spring Street, Long Beach, California.

This amendment (39-6177, AD 89-07-08) becomes effective on April 17, 1989.