AD 65-28-01

65-28-01 BRANTLY: Amdt. 39-168 Part 39 Federal Register December 14, 1965. Applies to Model B-2 Series Helicopters, Serial Number 454 and Below, Equipped with Tail Rotor Blades Assembly, P/N B2-111-11.

Compliance required as indicated, unless already accomplished.

To prevent further failures of the tail rotor blade grip at the outboard thrust bearing shoulder, accomplish the following:

(a) For helicopters with tail rotor blades assembly, P/N B2-111-11, with less than 100 hours' time in service on the effective date of this AD, comply with (c) through (g) before the accumulation of 125 hours' time in service.

(b) For helicopters with tail rotor blades assembly, P/N B2-111-11, with 100 or more hours' time in service on the effective date of this AD, comply with (c) through (g) within the next 25 hours' time in service.

(c) Remove and disassemble tail rotor blades assembly, P/N B2-111-11, from hub and thrust bearings in accordance with Brantly Model B2B Maintenance Manual.

(d) Using letter sealing wax or any other hard-setting, low-temperature-melting (250 degrees F. or less) material, make an impression of the thrust bearing shoulder relief radius in the grip at Blade Station 3.06, and inspect for a radius less than 0.020 inch.

(e) Using at least a two-power magnifying glass, inspect for sharp corner circumferential tool marks deeper than 0.010 inch.

(f) Remove from service any tail rotor blade with tool marks deeper than 0.010 inch or relief radius less than 0.020 inch before further flight.

(g) Reinstall any tail rotor blade with tool marks not deeper than 0.010 inch or relief radius not less than 0.020 inch in accordance with Brantly Model B2B Maintenance Manual.

This directive effective December 14, 1965