69-01-04 PRATT & WHITNEY: Amdt. 39-843. Applies to Pratt & Whitney Aircraft JT3D-1, JT3D-1- MC6, JT3D-1-MC7, JT3D-3, JT3D-3B and JT3D-7 Turbofan engines installed in Boeing Type 707 and 720 aircraft.
(a) To detect cracked No. 6 bearing oil tube assemblies, P/N 415907, 415908, 432000 or 432004, visually inspect daily the No. 6 bearing area, and visible portions of the 4th stage turbine rotor disc, and the bottom strut of the turbine exhaust strut assembly. Any oil wetness noted in these areas will require immediate inspection of the No. 6 bearing oil tube assemblies for possible cracks. If any cracks are found, the cracked tube assembly must be replaced prior to further flight except that the airplane may be flown in accordance with FAR 21.197 to a base where replacement parts are available.
(b) Replacement tubes of like part numbers as noted in paragraph (a) above shall continue to be inspected in accordance with this AD.
(c) Within 8000 hours' time in service after the effective date of this airworthiness directive, unless otherwise accomplished, replace all No. 6 bearing oil tube assemblies, P/N 415907, 415908, 432000, or 432004 with increased durability No. 6 bearing oil tube assemblies and support brackets as identified in Pratt & Whitney Aircraft Turbojet Engine Service Bulletin No. 2081 Revision No. 2 or later revision, approved by the Chief, Engineering and Manufacturing Branch, Eastern Region.
(d) This AD does not apply to engines incorporating increased durability No. 6 bearing oil tube assemblies and support brackets as identified in Pratt & Whitney Aircraft turbojet engine Service Bulletin No. 2081.
(e) Upon submission of substantiating data through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA Eastern Region may adjust the repetitive inspection specified in this AD.
Effective January 17, 1969.
Revised October 15, 1969.