78-11-03: First Stage Fan Blades

78-11-03 PRATT & WHITNEY AIRCRAFT: Amendment 39-3224. Applies to all Pratt & Whitney Aircraft JT3D turbofan engine models. Compliance required not later than March 1, 1980, unless already accomplished. To preclude failures of first stage fan blades due to forging laps, which could result in aircraft damage, perform a one-time blue etch anodize inspection of the blades in accordance with the procedures given in Pratt & Whitney Alert Service Bulletin 4733, dated May 5, 1977, or later FAA approved revision, and Special Instruction 2F-77, dated January 28, 1977, or later FAA approved revision. Fan blades that exhibit blue etch linear indications in the inspection areas shown in Figure 1 of ASB 4733 must be reworked or scrapped in accordance with the forging lap repair limits established in Figure 2 of ASB 4733, dated May 5, 1977, or later FAA approved revision. NOTE: The AD does not change the present fan blade blend limits given in the JT3D engine manual. Themanufacturer'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 Pratt & Whitney Aircraft, Division of United Technologies Corporation, 400 Main Street, East Hartford, Connecticut 06108. These documents may also be examined at Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803, and at FAA Headquarters, 800 Independence Avenue, S.W., Washington, D.C. This amendment becomes effective August 10, 1978.