71-02-02 PRATT & WHITNEY: Amdt. 39-1143 as amended by Amendment 39-1201. Applies to all Pratt & Whitney Aircraft JT4A series turbojet engines which incorporate the following serial number 12th stage compressor rotor disc part number 360112
1F-6145
3F-8849
4F-3831
4F-8300
5F-8122
1F-6150
3F-8850
4F-4569
4F-8301
5F-8123
1F-6151
through
4F-4570
5F-8342
2F-2758
3F-8855
4F-4642
4F-8458
5F-8346
2F-2759
4F-4643
5F-6445
5F-8405
2F-2764
3F-8856
4F-4645
5F-6446
5F-8510
2F-3781
3F-8920
4F-4648
5F-6447
5F-8512
3F-8921
5F-6449
2F-3785
3F-8923
4F-4747
5F-6452
5F-8522
2F-3788
3F-8924
4F-4748
5F-7606
5F-8529
2F-3926
3F-8926
4F-4749
5F-7748
5F-8589
2F-3927
3F-8927
4F-4750
5F-7749
through
3F-8928
4F-4752
5F-7835
2F-3933
3F-9114
4F-4968
5F-7837
2F-9674
3F-9115
4F-5029
5F-7838
2F-9675
3F-9116
through
5F-7839
2F-9676
4F-0454
4F-5035
5F-7840
2F-9677
4F-0461
4F-50595F-7867
3F-0551
4F-0465
through
5F-7872
through
4F-0467
4F-5063
5F-7875
3F-0558
4F-0471
4F-5087
5F-7985
4F-0473
4F-5089
5F-7987
3F-0559
4F-0475
4F-5090
5F-8031
3F-0560
4F-0477
4F-5091
5F-8032
3F-0563
4F-3606
5F-8035
4F-3690
4F-5092
4F-3692
through
5F-8039
4F-5099
5F-8042
4F-3699
5F-8119
4F-3700
4F-3828
4F-3830
Compliance required as indicated.
To preclude twelfth stage compressor rotor disc failure as the result of suspected material deficiency, accomplish the following:
(1) For all the previously listed serial number twelfth stage compressor rotor discs:
a. With 5000 cycles or more in service within the next 25 cycles in service after the effective date of this AD replace the suspect serial number disc.
b. With 5000 cycles or less in service prior to the accumulation of 5025 cycles in service replace the suspect serial number disc.
(2)Upon submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region, may adjust the compliance time.
Amendment 39-1143 was effective January 14, 1971 and was effective as to all recipients of the telegram dated 10 December 1970 which contained this airworthiness directive.
This Amendment 39-1201 is effective May 4, 1971.