AD 68-05-02

68-05-02 BRANTLY: Amdt. 39-572. Applies to Models B-2, B-2A and B-2B series helicopters with serial numbers 4 through 482 inclusive and Brantly Model 305 helicopters with serial numbers 1002 through 1045 inclusive.

Compliance required as indicated.

To prevent failure of the tail rotor drive shaft, accomplish the following:

(a) Within 10 hours' time in service after receipt of this Airworthiness Directive, unless already accomplished, inspect the tail rotor drive shaft for corrosion using a borescope and treat it with a corrosion preventive compound in accordance with Brantly Service Bulletin, SB No. B2B-68-2, dated February 24, 1968, or FAA-approved equivalent. After treatment, and before the tail rotor drive shaft plug is installed, reinspect the tail rotor drift shaft, using a borescope, to assure that the entire internal surface of the shaft is completely covered with the corrosion preventive compound.

(b) If corrosion is found as a result of the inspection required by paragraph (a) of this Airworthiness Directive which cannot be removed or leaves pits visible without magnification, disregard the treatment required by paragraph (a) of this Airworthiness Directive and prior to further flight replace the tail rotor drive shaft with a replacement part which complies with Brantly Service Bulletin, SB No. B2B-68-2, dated February 24, 1968, or FAA-approved equivalent.

This amendment becomes effective March 30, 1968