AD 87-25-51

87-25-51 AEROSPATIALE: Amendment 39-5828. Applies to all Model ATR-42 airplanes, certificated in any category. Compliance is required within the next 10 hours time-in-service, unless previously accomplished.

To prevent loss of aileron control due to autopilot servo freezing, accomplish the following:

A. Modify the autopilot roll actuator, part number 7002260-922, in accordance with paragraphs 2a, 2b, 2c, 2d, 2f, and 2g of Honeywell, Inc., Sperry Commercial Flight Systems Group, Service Bulletin 21-1987-063, dated October 20, 1987. In performing this modification, ensure that foreign debris does not enter the internal portions of the actuator.

B. Inspect all ATR-42 autopilot roll actuators, part number 7002260-922, to ensure that the rubber plug (part number 7013335) has not been installed in the drain hole.

C. An alternate means of compliance or adjustment of compliance time, which provides an acceptable level of safety and which has the concurrence of an FAAPrincipal Maintenance Inspector, may be used when approved by the Manager, Standardization Branch, ANM-113, FAA, Northwest Mountain Region.

All persons affected by this directive who have not already received the appropriate service documents from the manufacturer, may obtain copies upon request to Aerospatiale, 316 Route de Bayonne, 31060 Toulose Cedex 03, France, These documents may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington.

This amendment was effective earlier to all recipients of telegraphic AD T87-25-51, dated December 4, 1987.

This amendment 39-5828 becomes effective February 4, 1988.