70-11-04: Wood Main Rotor Blades

70-11-04 BELL: Amdt. 39-995. Applies to Bell Model 47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47H-1 helicopters, and to any other helicopters, equipped with wood main rotor blades and drag link equalizer horn, P/N 47-120-167-1. Compliance required within 50 hours' time in service after the effective date of this AD, unless already accomplished. To prevent possible failure of the drag link equalizer horn due to improper casting material, accomplish the one-time inspection for hardness as specified in Part I and Part II of Bell Helicopter Company Service Bulletin No. 144 SB dated October 9, 1969. Before further flight remove and replace horns having hardness values below those specified in Part II of Bell Helicopter Company Service Bulletin No. 144 SB. The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to the Service Manager, Bell Helicopter Company, P. O. Box 482, Fort Worth, Texas 76101. These documents may also be examined at the Office of the Regional Counsel, Southwest Region, FAA, 4400 Blue Mound Road, Fort Worth, Texas, and at FAA Headquarters, 800 Independence Avenue, S.W., Washington, D.C. A historical file on this AD which includes the incorporated material in full is maintained by the FAA at its headquarters in Washington, D.C., and at the Southwest Region Office in Fort Worth, Texas. This amendment becomes effective June 26, 1970.