AD 90-19-02

90-19-02 McDONNELL DOUGLAS HELICOPTER COMPANY (MDHC): Amendment 39-6716. Docket No. 89-ASW-44.

Applicability: All Model 369 series helicopters, certified in all categories, that are equipped with a cargo hook.

Compliance: Required as indicated, unless already accomplished.

To prevent an overrunning clutch assembly failure, which may result in the loss of engine power to the main rotor, accomplish the following:

(a) Within the next 300 hours' time in service after the effective date of this AD or at the next annual inspection, whichever occurs first, accomplish the following:

(1) Remove overrunning clutch assembly, part number (P/N) 369A5350- BSC, -601, or -603, if installed.

(2) Install the overrunning clutch subassembly, P/N 369A5350-41, in the clutch assembly, P/N 369A5350-BSC, -601, or -603, whichever is installed, or replace clutch assemblies with P/N 369A5350-605.

NOTE: Clutch subassembly, P/N 369A5350-31, can be converted to P/N 369A5350-41, in accordance with MDHC Service Information Notice (SIN) No. DN-164, EN-54, and FN-44, dated October 27, 1989. Clutch assemblies, P/N 369A5350-BSC, -601, or -603, can be reidentified as a -605 clutch assembly after installation of clutch subassembly, P/N 369A5350-41.

(b) Inspect the overrunning clutch assembly, P/N 369A5350-605 or P/N 369A5350- BSC, -601, or -603 with P/N 369A5350-41 subassembly, at intervals not to exceed 300 hours' time in service or at annual inspections, whichever occurs first, for condition of the race inner clutch, P/N 369A5353-3, the race outer clutch, P/N 369A5352, and the sprag assembly, P/N 369D25351.

(c) Replace sprag assemblies, P/N 369D25351 and P/N 369A5364, with an airworthy part on or before attaining 1,800 hours' total time in service.

NOTE: The Manufacturer's Handbook of Maintenance Instruction and the Component Overhaul Manual pertain to the removal, identification, and installation of these assemblies.

(d) Special flightpermits may be issued in accordance with FAR Sections 21.197 and 21.199 to operate helicopters to a base for the accomplishment of inspections required by this AD.

(e) Alternative inspections, modifications, or other actions which provide an equivalent level of safety may be used when approved by the Manager, Los Angeles Aircraft Certification Office, ANM-100L, FAA, Northwest Mountain Region, 3229 East Spring Street, Long Beach, California 90806-2425.

(f) For the purpose of establishing the "time in service" specified in this AD, either the clutch total time with hook attached may be used, or a separate and permanent log of external load operating time (take-off to landing on a flight which involves external load operations) may be used; this log must meet the requirements of FAR Section 91.173.

Airworthiness Directive 90-19-02 supersedes AD 81-07-10, Amendment 39-4077, as revised by Amendment 39-4266.

This amendment (39-6716, AD 90-19-02) becomes effective on October 5, 1990.