78-20-05 R4 SIKORSKY AIRCRAFT: Amendment 39-3305 as amended by Amendment 39-3425 and Amendment 39-3444 and 39-3838 is further amended by Amendment 39-4648. Applies to S-61 series helicopters certificated in all categories, including military counterparts, equipped with main rotor P/N S6112-23025-1 spindles (S6112-23027-006 spindle assemblies) and S6110-23325 series spindles (S6110-23327 series spindle assemblies).
Compliance required as indicated.
To preclude the possibility of failure of main rotor spindles, accomplish the following.
1. Within the next 20 hours' time in service, unless already accomplished within the last 50 hours' time in service, after the effective date of this amendment, and thereafter at intervals not to exceed 70 hours time in service, conduct ultrasonic inspections of all main rotor P/N S6112-23025-1 spindles (S6112-23027-006 spindle assemblies) and S6110-23325 series spindles (S6110-23327 series spindle assemblies), (plated and unplated), with 70 or more hours time in service, in accordance with the inspection method of Sikorsky Service Bulletin No. 61B10-33F, or an equivalent method approved by the Manager, Boston Aircraft Certification Branch, FAA, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803.
2. If a crack is found during the above inspections, replace the cracked spindle with a new spindle or a serviceable spindle prior to further flight.
3. Report in writing any cracks found during the above inspections to the Manager, Boston Aircraft Certification Branch, FAA, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803. Each report must include the length and location of the cracks and total time in service of the spindle (reporting approved by the Office of Management and Budget under OMB No. 04-R0174).
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 these documents from the manufacturer may obtain copies upon request to United Technologies Corporation, Sikorsky Aircraft, North Main Street, Stratford, Connecticut 06601, Attn: S-61 Commercial Product Support Department. These documents also may be examined in the Office of the Regional Counsel, Federal Aviation Administration, Southwest Region, 4400 Blue Mound Road, Fort Worth, Texas 76106.
Amendment 39-3305 became effective upon publication in the FEDERAL REGISTER for all persons except those to whom it was made effective immediately by telegram dated July 31, 1978.
Amendment 39-3425 became effective upon publication in the FEDERAL REGISTER.
Amendment 39-3444 became effective upon publication in the FEDERAL REGISTER for all persons except those to whom it was made effective immediately by telegram dated March 9, 1979.
Amendment 39-3838 became effective June30, 1980.
This Amendment 39-4648 becomes effective May 25, 1983.