AD 88-15-03

88-15-03 AEROSPATIALE: Amendment 39-5965. Applies to Model ATR-42 series airplanes, certificated in any category, as listed in the following Aerospatiale Service Bulletins: ATR42-27-0010, dated March 20, 1987; Operational Engineering Bulletin Number 17, dated January 26, 1987; ATR42-27-0015, Revision 3, dated February 29, 1988; ATR42-30-0010, Revision 2, dated July 7, 1987; and ATR42-21-0009, Revision 4, dated February 22, 1988.

Compliance is required as indicated, unless previously accomplished.

To prevent excessive loads on the vertical stabilizer in the event of dual hidden failures in the elevator trim system, accomplish the following:

A. For airplanes listed in Aerospatiale Service Bulletin ATR42-27-0010, dated March 20, 1987, within 100 hours time-in-service after the effective date of this AD, accomplish the following:

1. Inspect the trim system in accordance with Aerospatiale Service Bulletin ATR42-27-0010, dated March 20, 1987. Repeat this inspectionthereafter at intervals not to exceed 200 hours time-in-service. If defective parts are identified during this inspection, repair or replace with airworthy parts prior to further flight, in accordance with the service bulletin.

2. Insert the following in the Model ATR-42 Airplane Flight Manual, Limitations Section: "Prior to each taxi, perform the following procedure check: Prior to setting takeoff trim adjustment, run elevator trim to full up stop and full down stop to detect trim malfunction described in Operations Engineering Bulletin Number 17, dated January 26, 1987."

B. Within 1,500 hours time-in-service after the effective date of this AD:

1. For airplanes listed in Service Bulletin ATR42-21-0009, Revision 4, dated February 22, 1988: Install spike suppression circuits in the air conditioning system, in accordance with this service bulletin.

2. For airplanes listed in Aerospatiale Service Bulletin ATR42-27-0015, Revision 3, dated February 29, 1988: Subsequent to the installation of the spike suppression circuits required by paragraph B.1., above, install an elevator trim dissymmetry monitoring system and associated alarm, in accordance with this service bulletin.

3. For airplanes listed in Aerospatiale Service Bulletin ATR42-30-0010, Revision 2, dated July 7, 1987: Modify the crew warning system, in accordance with this service bulletin.

C. The accomplishment of the requirements of paragraph B., above, constitutes terminating action for the requirements of paragraph A., above.

D. 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, Standardization Branch, ANM-113, FAA, Northwest Mountain Region.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who may add any comments and then send it to the Manager, Standardization Branch, ANM-113.

E. Special flight permitsmay be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of the modifications required by 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 Aerospatiale, 316 Route de Bayonne, 31060 Toulouse Cedex 03, France. These documents may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or at the Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington.

This amendment, 39-5965, becomes effective August 11, 1988.