69-17-03 GENERAL ELECTRIC: Amdt. 39-824. Applies to General Electric Models CT58-100-1, CT58- 100-2, CT58-110-1, CT58-110-2, CT58-140-1, CT58-140-2, T58-GE-1 and T58-GE-5 engines, installed in Boeing Vertol 107 and Sikorsky S61 and S62 aircraft.
To prevent failures of first and second stage turbine rotor discs remove from service General Electric part numbers listed below with more than 10,100 cycles at the time of receipt of this telegram, unless already accomplished.
STAGE 1 DISCS STAGE 2 DISCS
278D978P002 278D979P002
37D400498P101 37D400499P101
37D400010P101 37D400004P102
37D400227P101 37D400228P102
37D400307P101 4002T96P01
4002T17P01
For the purposes of this airworthiness directive a cycle is considered as any engine operating sequence involving engine start, at least one acceleration to a power required for takeoff and shutdown.
Since it was found that immediate corrective action was required, notice and public procedure thereon was impracticable and contrary to the public interest and good cause existed for making the airworthiness directive effective immediately as to all known U.S. operators of Boeing Vertol 107 and Sikorsky S61 and S62 aircraft with General Electric Engine Models CT58-100-1, CT58-100-2, CT58-110-1, CT58-110-2, CT58-140-1, CT58- 140-2, T58-GE-1 and T58-GE-5, by individual telegrams dated August 12, 1969. These conditions still exist and the airworthiness directive is hereby published in the FEDERAL REGISTER as an amendment to Section 39.13 of Part 39 of the Federal Aviation Regulations to make it effective as to all persons.
This amendment becomes effective upon publication in the FEDERAL REGISTER for all persons except those to whom it was made effective immediately by telegram dated August 12, 1969.