AD 91-06-17

91-06-17 BOEING: Amendment 39-6931. Docket No. 90-NM-164-AD.

Applicability: Model 747-400 series airplanes through line number 791, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent the failure of either pilot's electronic flight instrument system (EFIS) control panel, with resultant smoke in the flight deck, accomplish the following:

A. Within 90 days after the effective date of this AD, inspect both EFIS control panels installed on the airplane and record the serial number and modification status. Control Panels with serial numbers identified in Collins Service Bulletin DCP-7000-31-04, dated December 1, 1989, and which do not have Modification 4 implemented, must be removed and modified in accordance with the service bulletin before further flight.

B. Any EFIS control panel with a serial number identified in Collins Service Bulletin DCP- 7000-31-04, dated December 1, 1989, and which does not have Modification 4 implemented, must be modified in accordance with the service bulletin before installation on an airplane.

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 (ACO), FAA, Transport Airplane Directorate.

NOTE: The request should be submitted directly to the Manager, Seattle ACO, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Seattle ACO.

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 Airplane Group, P.O. Box 3707, Seattle, Washington 98124; and Collins Air Transport Division/Rockwell International, 400 Collins Road N.E., Cedar Rapids, Iowa 52406. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington.

This amendment (39-6931, AD 91-06-17) becomes effective on April 15, 1991.