AD 90-02-04

90-02-04 BOEING OF CANADA, LTD., DE HAVILLAND DIVISION: Amendment 39- 6467. Docket No. 89-NM-207-AD. Applicability: Model DHC-8 series airplanes, serial numbers 3 through 144 inclusive; certificated in any category; equipped with main landing gear uplock actuator, Part Numbers 10800-103, -105, -107, -109, -111; and which do not have Modification 8/1098 incorporated.

Compliance: Required as indicated, unless previously accomplished.

To prevent failure of the main landing gear (MLG) to extend, accomplish the following:

A. Within 50 hours time-in-service after the effective date of this AD, inspect the MLG uplock installation in accordance with the compliance section of de Havilland Service Bulletin No. 8-32-79, Revision A, dated February 3, 1989. If the sensor bracket is under flush, and there are no spacers fitted, prior to further flight, rework the actuator in accordance with the service bulletin.

B. Whenever the proximity sensor and/or the proximity sensor mounting bracket on an uplock actuator has been reset or replaced, prior to further flight, perform the inspection and any necessary repair as required by paragraph A., above.

C. Within one year after the effective date of this AD, rework and reidentify all uplock actuators in accordance with DOWTY Alert Service Bulletin (part of de Havilland Service Bulletin No. 8-32-79) paragraph 2.E., "Rework" instructions. After rework is accomplished, the inspections required in paragraphs A. and B., above, may be terminated.

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, New York Aircraft Certification Office, FAA, New England 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, New York Aircraft Certification Office.

E. 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 of Canada, Ltd., de Havilland Division, Garrett Boulevard, Downsview, Ontario M3K 1Y5, Canada. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or the FAA, New England Region, New York Aircraft Certification Office, 181 South Franklin Avenue, Room 202, Valley Stream, New York.

This amendment (39-6467, AD 90-02-04) becomes effective on February 12, 1990.