61-22-08 SUD AVIATION: Amdt. 354 Part 507 Federal Register October 28, 1961. Applies to All Model SE 3130 Alouette II Helicopters.
Compliance required as indicated.
To remove defective bolts and preclude the possibility of further failure of the tail rotor gear box housing attachment the following inspections are required:
(a) The tail rotor gear box attachment bolts P/N 66.20.043 and tail rotor gear box guides P/N 66.20.213 shall be inspected within the next 10 hours' time in service in accordance with paragraphs (d) and (e) unless this inspection has already been complied with and/or the bolts replaced with parts that comply with paragraphs (d) and (e) subsequent to August 25, 1961.
(b) Every 50 hours' time in service subsequent to the completion of inspection prescribed in paragraph (a), reinspect and check the torque of the bolts and nuts P/N 66.20.043. The torque should be between 10.1 and 12.3 ft. lbs. If the bolts and nuts do not meet the torque requirements, remove the tail rotor gear box and inspect in accordance with paragraphs (d) and (e).
(c) Every 100 hours' time in service subsequent to completing inspection of paragraph (a), remove the tail rotor gear box and inspect the bolts and guides in accordance with paragraphs (d) and (e).
(d) The bolts P/N 66.20.043 are to be checked for cracks, corrosion, peeling and surface finish. Surface finish inspection is applicable to paragraph (a) only. Remove the zinc chromate protective finish, if applicable, by using paint remover. The diameter of the bolt bearing area at the head and at the thread end shall be measured in two directions 90 degrees apart in order to detect any out of round condition. These diameters shall not be less than 8.29 mm. (0.326 inch). The surface finish of the central necked down area and the radius at each end shall be as follows:
(1) The radius shall not be less than 1.61 mm. (0.0630 inch).
(2) The maximum permissible surface roughnessshall not exceed 1 micron (39 micro-inches).
(3) Localized defects no greater than 50 microns deep (1950 micro-inches) are permissible. If these standards are not met the bolts shall be replaced with bolts that do meet the standards.
(e) Check the bore of the three tail rotor gear box guides P/N 66.20.213 by measuring the bore along two directions 90 degrees apart. The bore dimension shall not exceed 8.33 mm. (0.328 inch). If these standards are not met the tail rotor gear box shall be replaced with a new or overhauled unit or the gear box returned to the factory or approved overhaul agency for installation of new guides before reinstallation on the helicopter.
(Sud Maintenance Manual Vol. I, Chapter 5, Pages 3 and 7, and Sud Service Bulletin No. 66-11-206 cover the same subject.)
This directive effective October 28, 1961.