81-21-06: Main Rotor Heads

81-21-06 SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE (SNIAS): Amendment 39-4226. Applies to all Model SA 330 series helicopters certificated in all categories. (Airworthiness Docket No. 81-ASW-42.) Compliance is required within 50 hours' time in service after the effective date of this AD, unless already accomplished. To ensure bearing lubrication and to prevent balls escaping from each main rotor blade lever assembly eyebolt pivot ball bearing, accomplish the following: (a) Applies to main rotor heads P/N 330A.31.0020 and 330A.31.0030, all dash numbers, not modified to AMS 07.43.008. Incorporate modification AMS 07.43.008 as described in paragraph 2, Accomplishment Instructions, of SNIAS Service Bulletin No. 65.30, dated November 20, 1979, or FAA approved equivalent. (b) Applies to main rotor heads P/N 330A.31.0020 and 330A.31.0030, all dash numbers, not modified to AMS 07.43.028. Incorporate modification AMS 07.43.028 as described in paragraph 2, Accomplishment Instructions, of SNIAS Service Bulletin No. 65.38, dated July 4, 1980, or FAA approved equivalent. (c) Applies to main rotor heads P/N 330A.31.0000.05 to .18 inclusive not modified to AMS 330A.07.43.038, and main rotor heads 330A.31.0020.00 to .04 inclusive not modified to AMS 330A.07.43.037, and main rotor heads P/N 330A.31.0030.00 to .03 inclusive not modified to AMS 330A.07.43.037. Inspect in accordance with paragraph C, Description, of SNIAS Service Bulletin No. 01.33, dated March 31, 1981, or FAA approved equivalent. Before further flight, replace bearings which are not fitted with sealing flange retaining ring, with serviceable bearings having the same MRC part number, that are fitted with the sealing flange retaining ring, or with serviceable bearings manufactured by FAFNIR, or with an FAA approved equivalent bearing. (d) Equivalent means of compliance with this AD must be approved by the Chief, Aircraft Certification Staff, AEU-100, Europe, Africa, and Middle East Office, Federal Aviation Administration, c/o American Embassy, Brussels Belgium. This amendment becomes effective October 12, 1981.