60-03-10 WRIGHT: Amdt. 90 Part 507 Federal Register January 26, 1960. Applies to All TC18DA and TC18EA Series Engines.
Compliance required at first engine overhaul after February 1, 1960, but not later than October 1, 1960.
To prevent inadvertent loss of oil from the power recovery turbine fluid couplings, the PRT oil control valve must incorporate a WAD P/N 147825 valve body, or subsequently released part. This valve body incorporates three flats to provide a permanent oil bypass to insure an adequate supply of turbine coupling oil in the event of a regulator spring failure. (WAD Service Bulletins Nos. TC18-390 and TC18E-210 cover this same subject and furnish instructions for the rework of the superseded valve bodies to the P/N 147825 configuration.)
This supersedes and cancels item No. (8) of AD 58-13-05.