AD 89-19-07

89-19-07 BOEING: Amendment 39-6322. (Docket No. 89-NM-48-AD) Applicability: Model 747 series airplanes, equipped with General Electric CF6-45 and CF6-50 engines, listed in Boeing Alert Service Bulletin 747-76A2071, Revision 1, dated January 26, 1989, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To eliminate the potential for uncommanded thrust operation due to engine control cable rupture, accomplish the following:

A. Within the next 60 days or 450 flight hours after the effective date of this AD, whichever occurs first, visually inspect the thrust control cables near the idler pulley for wear and strand separation, in accordance with the accomplishment instructions of Boeing Alert Service Bulletin 747-76A2071, Revision 1, dated January 26, 1989. If wear or strand separation is identified, replace the cable prior to further flight, in accordance with the service bulletin. Repeat the inspection at intervals not to exceed 600 flight hours.

B. Within one year after the effective date of this AD, install a pressure attenuator and attaching hardware to the engine-driven hydraulic pump in accordance with the accomplishment instructions of Service Bulletin 747-76A2071, Revision 1, dated January 26, 1989. This installation constitutes terminating action for the repetitive inspections required by paragraph A., above.

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 (39-6322, AD 89-19-07) becomes effective on October 14, 1989.