AD 88-18-05

88-18-05 SHORT BROTHERS, PLC: Amendment 39-5993. Applies to Model SD3-60 series airplanes, certificated in any category.

Compliance required as indicated, unless previously accomplished.

To prevent pitot tubes from becoming inoperative due to icing, which could result in erroneous airspeed and altitude indication, accomplish the following:

A. Within the next 180 days after the effective date of this AD, replace pitot tubes having the code letter "Z" adjacent to the serial number with one containing a code letter other than "Z," in accordance with accomplishment instructions in Service Bulletin SD360-34-09, dated March 1984.

B. 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 Manager, Standardization Branch, ANM-113.

C. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or 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 Short Brothers, PLC, Service Representative, 2011 Crystal Drive, Suite 713, Arlington, Virginia 22202-3702. 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, 39-5993, becomes effective September 7, 1988.