60-06-03: Tail Rotor Guard

60-06-03 BRANTLY: Amdt. 112 Part 507 Federal Register March 10, 1960. Applies to all Brantly B-2 helicopters Serial Numbers 1 through 29 with tail rotor guard upper fitting, P/N B2-416-2 installed. Compliance required within the next 10 hours' time in service and at each 10 hours' time in service thereafter. A fatigue crack has been found around the forward end of the weld joining the tail rotor guard to the sheet metal bracket at the upper tail rotor gear box. To preclude the possibility of the tail rotor loss because of entanglement with the tail rotor guard, the following shall be accomplished: (a) Remove paint in the area of the weld joining the upper guard fitting P/N B2-416- 2 and the tail rotor guard P/N B2-416-3 and inspect the weld area for cracks using a dye penetrant method or equivalent. (b) If a crack is found the defective parts must be replaced or repaired prior to further flight. The fitting may be repaired by stop drilling the crack and adding a reinforcing plate of 0.035 inch by 1 inch by 1 inch SAE 4130 steel over the crack, welding all four edges to P/N B2- 416-2. The reinforcing plate may be located under the head of the screw attaching the guard fitting to the tail rotor gear box, provided the plate is drilled for this screw and extends completely under the screw head. (c) When an improved upper fitting as specified in Brantly Service Bulletin No. 1 is incorporated, the provisions of this directive no longer apply.