AD 81-07-10 R1

This amendment amends an existing Airworthiness Directive (AD) applicable to Hughes Helicopters Model 369 series helicopters equipped with any cargo hook by clarifying cargo hook operating time recordation. This amendment is needed to relieve an undue burden on operations.

Accordingly, pursuant to the authority delegated to me by the Administrator, § 39.13 of Part 39 of the Federal Aviation Regulations (14 CFR 39.13) is amended, by amending Amendfnent 39-4077 (46 FR 20534), AD 81-07-10 by adding a new paragraph (f) to read as follows: * * * * * (f) For the purpose of establishing the “time in service” specified in paragraphs (a), (b), and (c) of this AD either the clutch total time with hook attached may be used, or a separate and permanent log of external load operating mission time (take-off to landing on a flight which involves external load operations), may be used. This log must meet the requirements of FAR 91.173.

Amendment 39-4077 (46 FR 20534), AD 81-07-10, currently imposes an inspection schedule on the overrunning clutch assembly P/N 369A5350-601 and a retirement life on P/N 369A5364 sprag assemblies on Hughes Helicopters Model 369 series helicopters equipped with any cargo hook. After issuing Amendment 39-4077, the FAA has determined that the basis of accumulating time in service on helicopters equipped with cargo hooks, for the purpose of establishing inspection intervals and retirement life, was unduly conservative. This conservatism was recognized at the time of issuance of Amendment 39-4077 but was considered necessary in the interests of safety in that there was no universal system for recording external load operation as a sub-element of total operating time, which is critical to this consideration. As a result of comments received since the issuance of Amendment 39- 4077, the FAA has reconsidered this matter and prescribed a method for universal recordation of external load operating (mission) time which will provide the relief requested by the commenters. Therefore, the FAA is amending Amendment 39-4077 by specifying a method of recording time in service relative to the inspection intervals of the overrunning clutch assembly and the establishment of a retirement life on the sprag assembly which is a part of the clutch assembly. Since this amendment provides a clarification only, and imposes no additional burden on any person, notice and public procedure hereon are unnecessary and good cause exists for making the amendment effective in less than 30 days.