62-14-05 PRATT & WHITNEY: Amdt. 451 Part 507 Federal Register June 14, 1962. Applies to All Pratt & Whitney Aircraft JT3D-1, JT3D-1-MC6, JT3D-1-MC7 and JT3D-3 Turbofan Engines equipped With Fourth Stage Turbine Rotor Blades P/N 395304 Change H or Earlier and P/N 434104 Change C or Earlier.
Compliance required at first engine overhaul after the effective date of this AD unless already accomplished.
As the result of fourth stage turbine rotor blade failures, the following is required.
Rework all P/N 395304 Change H or earlier and P/N 434104 Change C or earlier, fourth stage turbine rotor blades as follows:
(a) Rework these blades to incorporate a 55 degree tip shroud lock angle in accordance with P&WA telegraphic message dated August 17, 1961, to all JT3D operators.
(b) Rework the first serration of the blade root at both rear corner radii and the entire trailing edge of the airfoil section in accordance with Pratt & Whitney Aircraft Service Bulletin No. 387together with P&WA telegraphic message dated March 15, 1962, to all JT3D operators. Each blade must be fluorescent penetrant inspected prior to and after rework. Blades exhibiting any indications must be rejected.
(c) After completing of inspection, stress relieve all reworked blades at 1500 degrees F. plus or minus 25 degrees for four (4) hours. Glass bead peen the reworked area of the airfoil trailing edge in accordance with AMS-2430 to an intensity of 15N2.
NOTE: This AD does not apply to engines equipped with blades P/N 395304 Change J or later, P/N 434104 Change D or later, or P/N 434104 which carry the inscription PL-5651 or PL-5670 on the blade root.
(Pratt & Whitney Aircraft Service Bulletin No. 387 and P&WA telegraphic messages dated August 17, 1961, March 15, 1962, and March 21, 1962, to all JT3D operators, cover this same subject.)
This directive effective July 16, 1962.