AD 84-25-06 ACTIVE

84-25-06 HAMILTON STANDARD: Amendment 39-4970. Applies to Hamilton Standard Model 23LF-335 and -371 variable pitch propellers installed on, but not limited, to British Aerospace HP137 aircraft certificated in any category.

Compliance is required within the next 20 hours time in service or before the next propeller landing reversal, whichever occurs first, following the effective date of this AD, unless already accomplished, and at every 50 propeller landing reversals thereafter.

To detect cracks in the blades/counterweights which could cause possible propeller failure, accomplish the following:

(a) Clean and inspect for cracks in the propeller blades and counterweights in accordance with section 2, paragraphs A and B of Hamilton Standard ASB No. A27, Revision 1, November 1, 1984, or FAA approved equivalent.

(b) Blades and counterweights found to have evidence of cracks must be removed from service and replaced with a serviceable assembly prior to further flight.Aircraft may be ferried in accordance with the provisions of Federal Aviation Regulations (FARs) 21.197 and 21.199 to a base where the AD can be accomplished.

Upon request, an equivalent means of compliance with the requirements of this AD may be approved by the Manager, Engine and Propeller Standards Staff, ANE-110, FAA, 12 New England Executive Park, Burlington, Massachusetts 01803.

The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received this document from the manufacturer may obtain copies upon request to Hamilton Standard, Division of United Technologies Corporation, Windsor Locks, Connecticut 06096. These documents also may be examined at the Office of the Regional Counsel, FAA, Attn: Rule Docket No. 84-ANE-22, 12 New England Executive Park, Burlington, Massachusetts 01803.

This amendment becomes effective on January 3, 1985.