80-21-52 SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE: Amendment 39- 4380. Applies to Model SA-360C series helicopter, certificated in all categories.
Compliance required as indicated, unless already accomplished.
To prevent loss of main rotor speed due to a failure in the engine to main transmission connection, within 10 hours time in service after the effective date of this AD, accomplish the following:
(a) Visually inspect for cracks and other defects in the two half housings and the gimbal ring attachment flange.
NOTE: During the inspection required by paragraph (a) of this AD, particular attention should be directed to the attachment points/areas.
(b) Remove the upper housing half and visually inspect the flexible couplings on the clutch and main transmission sides at the attachment points for cracks, breaks, distortion, and fretting corrosion.
(c) Remove the nut from one of the bolts attaching the flexible coupling and check for correct positioning of the flectors.
NOTE: 1. The press-fit area of the flector bushings should be located on the flange side.
2. Upon re-installation of the nut, dry torque the nut to 4 to 5 mdaN. (30-35 ft lbs).
(d) Check the condition of the main transmission input coupling flange for marks, scores, and impacts.
(e) If during the inspections and checks required by paragraphs (a), (b), (c), and (d) of this AD, a crack is found, inspect the main transmission flange for cracks using the dye penetrant method.
(f) If cracks are found during the inspections and checks required by paragraphs (a), (b), or (e) of this AD, before further flight, except as provided by paragraph (h) of this AD, replace the main transmission housing and gimbal ring attachment flange with a serviceable part.
(g) If no cracks are found during the inspections and checks required by paragraphs (a), (b), (c), (d), or (e) of this AD, repair other defects as necessary.
(h) The helicopter may be flown in accordance with FAR 21.197 and FAR 21.199 to a base where the inspections and repairs required by this AD can be accomplished provided paragraph (a) of this AD has been accomplished.
(i) Report defects found to the Chief, Aircraft Certification Staff, Europe, Africa and Middle East Office, FAA, c/o American Embassy, Brussels, Belgium. Reporting approved by the Office of Management and Budget OMB No. 04-R0174.
NOTE: Aerospatiale Work Cards No. 65-31-601, dated November 1976, and No. 65-31- 401, dated June 1975, and Section 02.80 of the Aerospatiale Standard Practices Manual, refer to the inspections and checks required by this AD.
This amendment becomes effective May 6, 1981, as to all persons except those persons to whom it was made immediately effective by telegraphic AD T80-21-52, issued October 8, 1980, which contained this amendment.