AD 67-11-03

67-11-03 HUGHES: Amdt. 39-389, Part 39, Federal Register April 7, 1967. Applies to Models 269A, 269A-1, 269A-2, and 269B Series Helicopters Equipped with Main Rotor Gear Drive Assembly P/N 269A5175 Bearing Serial Numbers 0001 to 1424 Inclusive.

Compliance required within the next 25 hours time in service for all aircraft unless already accomplished.

To prevent malfunction of the main rotor gear drive assembly P/N 269A5175 caused by failure of the huck bolts P/N SALP-T10-7 that attach the main rotor drive shaft coupling to the ring gear carrier, and to detect damage that may have resulted from operation of the helicopter with the huck bolts installed, accomplish the following in accordance with Hughes Service Information Notice No. N-29 or later FAA-approved revision unless otherwise specified herein:

(a) Remove huck bolts P/N SALP-T10-7 and collars P/N 6LC-C10 from the main rotor gear drive assembly P/N 269A5175. Visually inspect the resulting holes for deformity orother damage and check the vertical and horizontal diameters of the holes by means of a hole gauge. Line ream all out-of-tolerance holes to correspond to the tolerance specified for the holes.

(b) Replace huck bolts P/N SALP-T10-7 and collars P/N 6LC-C10, respectively, with Hi-Lok bolts P/N's HL-20-PB-10-7, HL-20-PB-10-8, or HL-64-PB10-7 and collars P/N HL 87-10.

(c) Inspect the main rotor gear drive assembly P/N 269A5175 for defects specified in Hughes Service Information Notice No. N-29 or later FAA-approved revision. If defects are observed, maintain the affected part or parts in accordance with Hughes Handbook of Maintenance Instructions applicable to the particular helicopter model (including the Overhaul Addendum for the Main Rotor Gear drive Assembly applicable to all helicopter models) or in accordance with a method approved by the Chief, Aircraft Engineering Division, FAA Western Region.

(d) Operators who have not kept records of hours' time in service of individual main rotor gear drive assemblies shall substitute in lieu thereof hours' time in service of the helicopter.

This directive effective April 7, 1967.

Revised May 30, 1967.