AD 97-11-51 R1 ACTIVE

This amendment adopts a new airworthiness directive (AD) that is applicable to Pratt & Whitney PW2000 series turbofan engines. This action revises telegraphic AD T97-11-51 that currently supersedes AD 97-09-01 by correcting errors in the Serial Number (S/N) tables, and removing the McDonnell Douglas C-17 aircraft from the applicability section, as a different model engine is installed on McDonnell Douglas C-17 aircraft. In addition, that telegraphic AD clarifies that inspections must be performed prior to rework, and clarifies that new parts do not need to be reworked prior to installation, but must be reworked at the next shop visit. Finally, that telegraphic AD makes minor editorial changes for clarity without changing meaning or intent. This action relaxes the compliance intervals for rework and provides relieving requirements. This amendment is prompted by industry input and resulting changes by the manufacturer to the inspection program that would provide relief tooperators while maintaining an equivalent level of safety. The actions specified by this AD are intended to prevent fracture of the first stage high pressure turbine (HPT) disk, resulting in a possible uncontained engine failure and damage to the aircraft.

Final rule; request for comments.

97-11-51 R1 Pratt & Whitney: Amendment 39-10094. Docket No. 97-ANE-25-AD. Revises Telegraphic AD T97-11-51.
Applicability: Pratt & Whitney (PW) PW2000 series turbofan engines, with first stage high pressure turbine (HPT) disk assembly, Part Numbers (P/N) 1A5921, 1B2671, and 1B3621, installed. These engines are installed on but not limited to Boeing 757 series and Ilyushin IL-96 series aircraft.
Note 1: This airworthiness directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (l) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair onthe unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
Compliance: Required as indicated, unless accomplished previously.
To prevent fracture of the first stage HPT disk, resulting in a possible uncontained engine failure and damage to the aircraft, accomplish the following:
(a) Prior to further flight, for first stage HPT disks that are accessible in the shop, on the effective date of this AD, as defined in paragraph (k)(2) of this AD, and that have not been eddy current inspected in accordance with the Accomplishment Instructions of PW Service Bulletin (SB) No. PW2000 72-588, Revision 1, dated March 31, 1997, or Original, dated February 17, 1997, perform eddy current inspection (ECI) of the first stage HPT disks for cracks in the forward face of the disk at the base of the fir tree lug at the outer diameter (OD) snap fillet radius where the side plates mate with thedisk, in accordance with the Accomplishment Instructions of PW SB No. PW2000 72-588, Revision 1, dated March 31, 1997, or Original, dated February 17, 1997.
(b) For first stage HPT disks that are identified by serial number (S/N) in Table 1 of this AD, and have not been eddy current inspected in accordance with the Accomplishment Instructions of PW SB No. PW2000 72-588, Revision 1, dated March 31, 1997, or Original, dated February 17, 1997, accomplish the following:

TABLE 1

L82270
M68538
N11397
N54412
P36638
P91935
R28848
L82271
M68539
N11398
N54413
P36639
R28552
R28901
L82272
M68540
N11399
N54414
P36805
R28553
R28903
L82356
M68541
N11400
N54415
P36806
R28554
R28904
L82649
M68696
N11401
N54416
P37113
R28555
R28905
L82650
M68697
N11402
N54417
P37114
R28612
R28906
L83308
M68698
N11403
N54418
P37115
R28613
R28907
L83309
M68699
N11404
N54419
P37116
R28614
R28908
L83310
M68700
N11405
N55114
P37117
R28615R28909
L83311
M68701
N11406
N55115
P37118
R28617
R28913
L83312
M68702
N11407
N55116
P37324
R28618
R28914
M15709
M68703
N12830
N55117
P37325
R28680
R28915
M15710
M68915
N12831
P00624
P37326
R28681
R28933
M15718
M68916
N12832
P00625
P37327
R28682
R28934
M42710
M68917
N12833
P00626
P37328
R28683
R28935
M42711
M68918
N12834
P00627
P37348
R28684
R28936
M42768
M68919
N12835
P00628
P37349
R28685
R28937
M42769
M68997
N12836
P00788
P37351
R28686
R28951
M42770
M68998
N12838
P00812
P37352
R28687
R28952
M42771
M69000
N12839
P00813
P37353
R28711
R28953
M43103
M69001
N12840
P00814
P37354
R28712
R28954
M43104
M85382
N12841
P00815
P90203
R28713
R28955
M43105
M85383
N12842
P00816
P90204
R28714
R28956
M43396
M85384
N12843
P00817
P90205
R28715
S16633
M43397
M85385
N12844
P00818
P90206
R28716
S16634
M43398
M85386
N12845
P00986
P90207
R28718
S16636
M43399
M85387
N12846P00987
P90208
R28719
S16637
M43400
N09764
N12847
P01018
P90209
R28720
S16638
M43401
N09765
N12848
P01457
P90210
R28752
S16639
M43409
N09766
N54390
P36249
P90211
R28753
S16641
M43410
N09767
N54391
P36250
P90212
R28755
S16642
M43411
N09768
N54392
P36251
P90385
R28756
S16643
M68250
N09769
N54393
P36252
P90386
R28757
S16645
M68251
N09770
N54395
P36253
P90387
R28758
S16646
M68252
N09771
N54396
P36254
P90388
R28761
S16647
M68253
N09772
N54397
P36255
P90389
R28800
S16648
M68254
N09773
N54398
P36256
P90390
R28801
S16649
M68255
N09774
N54399
P36258
P91685
R28802
S16650
M68256
N09775
N54400
P36259
P91686
R28803
S16651
M68344
N09776
N54401
P36306
P91687
R28804
S16658
M68345
N09777
N54402
P36307
P91688
R28805
S16659
M68346
N09778
N54403
P36308
P91854
R28806
S16660
M68347
N11389
N54404
P36309
P91855
R28807
S16662
M68348
N11390
N54405
P36310
P91856
R28808
S16666M68349
N11391
N54406
P36311
P91857
R28809
S16678
M68350
N11392
N54407
P36312
P91867
R28810
S16687
M68536
N11393
N54408
P36378
P91931
R28811

M68537
N11394
N54409
P36634
P91932
R28812

N11395
N54410
P36636
P91933
R28813

N11396
N54411
P36637
P91934
R28847

(1) For disks that have accumulated 10,000 or more cycles since new (CSN) on the effective date of this AD, accomplish the following:
(i) Perform an inspection for cracks and rework within 1,600 CIS after the effective date of this AD in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997, or
Note 2: Throughout this AD, Pratt & Whitney ASB No. PW2000 A72-592, dated March 18, 1997, describes returning the part to designated overhaul shops for modifications. The modifications described in that ASB are performed by the overhaul shops and include inspections prior to and after rework.
(ii) Perform a double independent inspection for cracks, as defined in paragraph (k)(3) of this AD, within 1,600 cycles in service (CIS) after the effective date of this AD, in accordance with the Accomplishment Instructions of PW SB No. PW2000 72-588, Revision 1, dated March 31, 1997, or Original, dated February 17, 1997.
(iii) If the disk is double inspected in accordance with paragraph (b)(1)(ii) of this AD, then inspect the disk for cracks and rework at the next shop visit after the completion of the double inspection, but not to exceed 4,000 CIS since the double inspection, in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997.
(2) For disks that have accumulated less than 10,000 CSN on the effective date of this AD, accomplish the following:
(i) Perform an inspection for cracks and rework at the next shop visit after the effective date of this AD, or 11,600 CSN, whichever occurs first, in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997, or
(ii) Perform a double independent inspection for cracks, as defined in paragraph (k)(3) of this AD, at the next shop visit after the effective date of this AD, not to exceed 11,600 CSN, in accordance with the Accomplishment Instructions of PW SB No. PW2000 72-588, Revision 1, dated March 31, 1997, or Original, dated February 17, 1997.
(iii) If the disk is double inspected in accordance with paragraph (b)(2)(ii) of this AD, then inspect the disk for cracks and rework at the next shop visit after the completion of the double inspection, but not to exceed 4,000 CIS since the double inspection, in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997.
(c) For first stage HPT disks that are identified by S/N in Table 2 of this AD, and that have not been eddy current inspected in accordance with the Accomplishment Instructions of PW SB No. PW2000 72-588, Revision 1, dated March 31, 1997, or Original, dated February 17, 1997, accomplish the following:
TABLE 2

D301AA0011
S16682
S16713
S16746
S16780
D301AA0032
S16683
S16715
S16747
S16783
S16652
S16684
S16716
S16748
S16787
S16654
S16685
S16717
S16749
S16795
S16655
S16688
S16718
S16750

S16656
S16689
S16719
S16751

S16657
S16690
S16720
S16752

S16661
S16691
S16721
S16753

S16663
S16692
S16723
S16756

S16664
S16693
S16724
S16757

S16665
S16694
S16725
S16758

S16667
S16695
S16727
S16760

S16668
S16697
S16728
S16761

S16669
S16698
S16730
S16762

S16670
S16699
S16731
S16763

S16671
S16700
S16732
S16765

S16672
S16701
S16733
S16766

S16673
S16702
S16735
S16768

S16674
S16703
S16738
S16769

S16675
S16705
S16739
S16772

S16676
S16707
S16741
S16773

S16677
S16708
S16742
S16774

S16679
S16709
S16743
S16775

S16680
S16710
S16744
S16776

S16681
S16712
S16745
S16777

(1) For disks that have accumulated 7,000 or more CSN on the effective date of this AD, accomplish the following:
(i) Perform an inspection for cracks andrework within 800 CIS after the effective date of this AD in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997, or
(ii) Perform a double independent inspection for cracks, as defined in paragraph (k)(3) of this AD, within 800 CIS after the effective date of this AD, in accordance with the Accomplishment Instructions of PW SB No. PW2000 72-588, Revision 1, dated March 31, 1997, or Original, dated February 17, 1997.
(iii) If the disk is double inspected in accordance with paragraph (c)(1)(ii) of this AD, then inspect the disk for cracks and rework at the next shop visit after the completion of the double inspection, but not to exceed 4,000 CIS since the double inspection, in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997.
(2) For disks that have accumulated less than 7,000 CSN on the effective date of this AD, accomplish the following:
(i) Perform an inspection for cracks and rework at the next shop visit after the effective date of thisAD, or 7,800 CSN, whichever occurs first, in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997, or
(ii) Perform a double independent inspection for cracks, as defined in paragraph (k)(3) of this AD, at the next shop visit after the effective date of this AD, not to exceed 7,800 CSN, in accordance with the Accomplishment Instructions of PW SB No. PW2000 72-588, Revision 1, dated March 31, 1997, or Original, dated February 17, 1997.
(iii) If the disk is double inspected in accordance with paragraph (c)(2)(ii) of this AD, then inspect the disk for cracks and rework at the next shop visit after the completion of the double inspection, but not to exceed 4,000 CIS since the double inspection, in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997.
(d) For first stage HPT disks that are identified by S/N in Table 3 of this AD, and that have not been eddy current inspected in accordance with the Accomplishment Instructions of PW SB No. PW2000 72-588, Revision 1, dated March 31, 1997, or Original, dated February 17, 1997, accomplish the following:

TABLE 3

D301AA0002
D301AA0118
D301AA0414
DKLBA78514
DKLBA78646
D301AA0003
D301AA0121
D301AA0415
DKLBA78515
DKLBA78648
D301AA0004
D301AA0123
D301AA0416
DKLBA78517
DKLBA78649
D301AA0005
D301AA0124
D301AA0418
DKLBA78518
DKLBA78650
D301AA0006
D301AA0125
D301AA0419
DKLBA78519
DKLBA78651
D301AA0008
D301AA0127
D301AA0420
DKLBA78520
DKLBA78652
D301AA0009
D301AA0129
D301AA0421
DKLBA78521
DKLBA78653
D301AA0010
D301AA0130
D301AA0422
DKLBA78522
DKLBA78654
D301AA0013
D301AA0131
D301AA0423
DKLBA78524
DKLBA78655
D301AA0015
D301AA0132
D301AA0424
DKLBA78525
DKLBA78656
D301AA0018
D301AA0133
D301AA0425
DKLBA78526
DKLBA78657
D301AA0019
D301AA0135
D301AA0426
DKLBA78527
DKLBA78658
D301AA0020
D301AA0137
D301AA0427
DKLBA78528
DKLBA78660
D301AA0021
D301AA0138
D301AA0428
DKLBA78529
DKLBA78661
D301AA0022
D301AA0140
D301AA0431
DKLBA78530
DKLBAH8318
D301AA0023
D301AA0141
D301AA0432
DKLBA78531
DKLBAH8319
D301AA0024
D301AA0144
D301AA0434
DKLBA78533
DKLBAH8320
D301AA0025
D301AA0145
D301AA0435
DKLBA78534
DKLBAH8321
D301AA0027
D301AA0146
D301AA0437
DKLBA78536
DKLBAH8322
D301AA0028
D301AA0147
D301AA0438
DKLBA78537
DKLBAH8323
D301AA0029
D301AA0148
D301AA0439
DKLBA78538
DKLBAH8324
D301AA0031
D301AA0149
D301AA0440
DKLBA78540
DKLBAH8325
D301AA0033
D301AA0150
D301AA0443
DKLBA78541
DKLBAH8327
D301AA0034
D301AA0151
D301AA0444
DKLBA78542
DKLBAH8328
D301AA0035
D301AA0152
D301AA0445
DKLBA78543
DKLBAH8329
D301AA0038
D301AA0154
D301AA0446
DKLBA78544
DKLBAH8330
D301AA0039
D301AA0156
D301AA0447
DKLBA78545
DKLBAH8331
D301AA0040
D301AA0157
D301AA0449
DKLBA78550
DKLBAH8332
D301AA0041
D301AA0159
D301AA0450
DKLBA78551
DKLBAH8333
D301AA0042
D301AA0161
DKLBA78421
DKLBA78552
DKLBAH8336
D301AA0044
D301AA0163
DKLBA78423
DKLBA78553
DKLBAH8337
D301AA0045
D301AA0164
DKLBA78427
DKLBA78554
DKLBAH8339
D301AA0046
D301AA0165
DKLBA78429
DKLBA78557
DKLBAH8340
D301AA0047
D301AA0166
DKLBA78431
DKLBA78558
DKLBAH8343
D301AA0048
D301AA0167
DKLBA78432
DKLBA78559
DKLBAH8344
D301AA0049
D301AA0171
DKLBA78433
DKLBA78560
DKLBAH8346
D301AA0050
D301AA0174
DKLBA78434
DKLBA78561
DKLBAH8347
D301AA0051
D301AA0175
DKLBA78435
DKLBA78562
DKLBAH8348
D301AA0052
D301AA0177
DKLBA78436
DKLBA78564
DKLBAH8349
D301AA0053
D301AA0179
DKLBA78437
DKLBA78568
DKLBAH8350
D301AA0054
D301AA0180
DKLBA78438
DKLBA78569
DKLBAH8351
D301AA0055
D301AA0182
DKLBA78439
DKLBA78575
DKLBAH8352
D301AA0056
D301AA0187
DKLBA78441
DKLBA78577
DKLBAH8353
D301AA0057
D301AA0189
DKLBA78442
DKLBA78578
DKLBAH8354
D301AA0059
D301AA0198
DKLBA78443
DKLBA78579
DKLBAH8355
D301AA0061
D301AA0201
DKLBA78444
DKLBA78580
DKLBAH8356
D301AA0062
D301AA0205
DKLBA78446
DKLBA78581
DKLBAH8357
D301AA0064
D301AA0358
DKLBA78448
DKLBA78582
DKLBAH8360
D301AA0065
D301AA0359
DKLBA78449
DKLBA78584
DKLBAH8361
D301AA0066
D301AA0360
DKLBA78453
DKLBA78585
DKLBAH8362
D301AA0067
D301AA0361
DKLBA78454
DKLBA78587
DKLBAH8364
D301AA0068
D301AA0362
DKLBA78455
DKLBA78589
DKLBAH8365
D301AA0069
D301AA0363
DKLBA78456
DKLBA78590
DKLBAM0972
D301AA0070
D301AA0364
DKLBA78457
DKLBA78593
DKLBAM0973
D301AA0071
D301AA0367
DKLBA78458
DKLBA78594
S16778
D301AA0072
D301AA0368
DKLBA78459
DKLBA78596
S16782
D301AA0074
D301AA0369
DKLBA78465
DKLBA78598
S16784
D301AA0075
D301AA0370
DKLBA78467
DKLBA78600
S16786
D301AA0077
D301AA0371
DKLBA78468
DKLBA78601
S16789
D301AA0080
D301AA0372
DKLBA78469
DKLBA78603
S16790
D301AA0081
D301AA0375
DKLBA78472
DKLBA78604
S16792
D301AA0082
D301AA0376
DKLBA78475
DKLBA78605
S16793
D301AA0083
D301AA0377
DKLBA78482
DKLBA78606
S16798
D301AA0084
D301AA0379
DKLBA78483
DKLBA78607
S16800
D301AA0085
D301AA0380
DKLBA78484
DKLBA78609
S16802
D301AA0086
D301AA0381
DKLBA78485
DKLBA78610
S16803
D301AA0087
D301AA0382
DKLBA78486
DKLBA78611
S16804
D301AA0088
D301AA0383
DKLBA78487
DKLBA78613
S16805
D301AA0089
D301AA0384
DKLBA78488
DKLBA78614
S16806
D301AA0090
D301AA0386
DKLBA78489
DKLBA78615
S16807
D301AA0091
D301AA0387
DKLBA78490
DKLBA78616
S16808
D301AA0092
D301AA0388
DKLBA78491
DKLBA78617
S16810
D301AA0093
D301AA0390
DKLBA78492
DKLBA78618
S16811
D301AA0094
D301AA0391
DKLBA78493
DKLBA78620
S16814
D301AA0095
D301AA0392
DKLBA78496
DKLBA78622
S16815
D301AA0096
D301AA0393
DKLBA78497
DKLBA78625
S16816
D301AA0098
D301AA0394
DKLBA78498
DKLBA78627
S16818
D301AA0101
D301AA0395
DKLBA78500
DKLBA78628
S16819
D301AA0102
D301AA0396
DKLBA78502
DKLBA78632
S16821
D301AA0103
D301AA0399
DKLBA78503
DKLBA78633
S16822
D301AA0104
D301AA0401
DKLBA78504
DKLBA78635
S16824
D301AA0105
D301AA0402
DKLBA78505
DKLBA78636
S16825
D301AA0106
D301AA0403
DKLBA78506
DKLBA78638
S16827
D301AA0107
D301AA0404
DKLBA78507
DKLBA78639
S16829
D301AA0108
D301AA0406
DKLBA78508
DKLBA78640
S16831
D301AA0110
D301AA0407
DKLBA78509
DKLBA78642
S16832
D301AA0111
D301AA0408
DKLBA78510
DKLBA78644

D301AA0114
D301AA0412
DKLBA78512
DKLBA78645

(1) For disks that have accumulated 7,000 or more CSN on the effective date of this AD accomplish the following:
(i) Perform an inspection for cracks and rework within 1,100 CIS after the effective date of this AD in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997, or
(ii) Perform a double independent inspection for cracks, as defined in paragraph (k)(3) of this AD, within 1,100 CIS after the effective date of this AD, in accordance with the Accomplishment Instructions of PW SB No. PW2000 72-588, Revision 1, dated March 31, 1997, or Original, dated February 17, 1997.
(iii) If the disk is double inspected in accordance with paragraph (d)(1)(ii) of this AD, then inspect the disk for cracks and rework at the next shop visit after the completion of the double inspection, but not to exceed 2,450 CIS since the double inspection, in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997.
(2) For disks that have accumulated less than 7,000 CSN on the effective date of this AD, accomplish the following:
(i) Perform an inspection for cracks and rework at the next shop visit after the effective date of this AD, or 8,100 CSN, whichever occurs first, in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997, or
(ii) Perform a double independent inspection for cracks, as defined in paragraph (k)(3) of this AD, at the next shop visit after the effective date of this AD, not to exceed 8,100 CSN, in accordance with the Accomplishment Instructions of PW SB No. PW2000 72-588, Revision 1, dated March 31, 1997, or Original, dated February 17, 1997.
(iii) If the disk is double inspected in accordance with paragraph (d)(2)(ii) of this AD, then inspect the disk for cracks and rework at the next shop visit after the completion of the double inspection, but not to exceed 2,450 CIS since the double inspection, in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997.
(e) For disks that have been inspected in accordance with PW SB No. PW2000 72-588, Revision 1, dated March 31, 1997, or Original, dated February 17, 1997, but not reworked in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997, inspect for cracks and rework in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997, at the next shop visit when the part is accessible, as defined in paragraph (k)(2) of this AD, or 4,000 CIS since last ECI in accordance with PW SB No. PW2000 72-588, Revision 1, dated March 31, 1997, or Original, dated February 17, 1997, whichever occurs first.
(f) Prior to further flight, remove and replace disks with cracks. Disks with cracks cannot be reworked.
(g)If reworked, reidentify the disk in accordance with the Accomplishment Instructions of PW ASB No. PW2000 A72-592, dated March 18, 1997.
(h) For all first stage HPT disks that have been reworked in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997, inspect in accordance with PW Engine Manual, P/N 1A6231, Section 72-52-02, Inspection Check 04, at each subsequent shop visit when the disk is accessible, as defined in paragraph (k)(2) of this AD, not to exceed 6,000 CIS since last inspection.
(i) The following cyclic life limits apply to disks that are reworked in accordance with the Accomplishment Instructions of PW ASB No. PW2000 A72-592, dated March 18, 1997:
(1) Disks that have accumulated less than 5,000 CSN upon rework may accumulate an additional 10,000 CIS following rework, and then must be retired from service.
(2) Disks that have accumulated 5,000 CSN or more upon rework may remain in service to the full 15,000 CSN published life limit, and then must be retired from service.
(3) Except as provided in paragraph (l) of this AD, no alternative life limits may be approved for disks reworked in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997.
(j) Operators may install new, unused first stage HPT disks without inspection and rework in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997, but must inspect and rework those disks at the next shop visit when the disk is accessible, as defined in paragraph (k)(2) of this AD, or 6,500 CSN, whichever occurs first, in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997, as defined in paragraphs (b) through (d), and (f) through (i) of this AD.
(k) For the purpose of this AD, the following definitions apply:
(1) A shop visit is defined as an engine removal where engine maintenance, prior to reinstalling the engine, entails separation of pairs of mating major engine flanges or the removal of a disk, hub, or spool.
(2) An accessible disk is defined as a disk that is in the shop, has been removed from the HPT module, separated from the rotor, and debladed.
(3) A double independent inspection is defined as having two independent qualified inspectors perform a complete ECI of the disk in accordance with the inspection requirements described in the Accomplishment Instructions of PW SB No. PW2000 72-588, Revision 1, dated March 31, 1997, or Original, dated February 17, 1997. Each inspector shall perform an independent calibration of the ECI equipment prior to performing the ECI in accordance with that SB.
(l) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Engine Certification Office. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office.
Note 3: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine Certification Office.
(m) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the inspection and rework requirements of this AD can be accomplished.
(n) The actions required by this AD shall be accomplished in accordance with the following PW service documents:

Document No.
Pages
Revision
Date
SB No. PW2000 72-588
1
1
March 31, 1997

2
Original
February 17, 1997

3-12
1
March 31, 1997
NDIP-899
1-23
A
March 25, 1997

38
Original
February 17, 1997
Total pages: 36.

SB No. PW2000 72-588
1-12
Original
February 17, 1997

38
Original
February 17, 1997
NDIP-899
1-23
Original
February 16, 1997
Total pages: 36.

ASB No. PW2000 A72-592
1-16
Original
March 18, 1997
Total pages: 16.

This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone (860) 565-6600, fax (860) 565-4503. Copies may be inspected at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
(o) This amendment becomes effective on August 7, 1997.

On May 12, 1997, the Federal Aviation Administration (FAA) issued telegraphic airworthiness directive (AD) T97-11-51, applicable to Pratt & Whitney (PW) PW2000 series turbofan engines, which supersedes AD 97-09-01 by correcting errors in the Serial Number (S/N) tables, and removing the McDonnell Douglas C-17 aircraft from the applicability section, as a different model engine is installed on McDonnell Douglas C-17 aircraft. In addition, that AD clarifies that inspections must be performed prior to rework, and clarifies that new parts do not need to be reworked prior to installation, but must be reworked at the next shop visit. Finally, that AD makes minor editorial changes for clarity without changing meaning or intent. That action was prompted by comments from the manufacturer received in response to AD 97-09-01 that require the FAA to issue immediate changes and corrections to the compliance section prior to initiating the inspection and rework programdescribed in the AD 97-09-01. Airworthiness directive 97-09-01 was prompted by reports of two uncontained disk failures resulting from a fir tree lug fracturing, that subsequently released two blades and a fir tree lug, that penetrated the engine high pressure turbine (HPT) case. That condition, if not corrected, could result in fracture of the first stage HPT disk, resulting in a possible uncontained engine failure and damage to the aircraft.
Since the issuance of that telegraphic AD, the FAA has received changes from the manufacturer to the inspection program that would provide relief to operators while maintaining an equivalent level of safety.
The FAA has reviewed and approved the technical contents of PW Service Bulletin (SB) No. PW2000 72-588, Revision 1, dated March 31, 1997, and Original, dated February 17, 1997, that describe procedures for inspections for cracks in the forward face of the first stage HPT disk at the base of the fir tree lug at the outer diameter (OD)snap fillet radius where the side plates mate with the disk utilizing an eddy current inspection technique, and PW Alert Service Bulletin (ASB) No. PW2000 A72-592, dated March 18, 1997, that describes procedures for rework to the forward and aft faces of the first stage HPT disk OD snap fillet radii at the base of the fir tree lug.
Since an unsafe condition has been identified that is likely to exist or develop on other engines of this same type design, this AD revises telegraphic AD T97-11-51 to relax the compliance intervals for rework and provide relieving requirements by adding an optional double independent eddy current inspection. The actions are required to be accomplished in accordance with the service documents described previously.
Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. Comments Invited
Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.
Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspectsof the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 97-ANE-25-AD." The postcard will be date stamped and returned to the commenter.
The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive:

Submit comments in triplicate to the Federal Aviation Administration (FAA), New
England Region, Office of the Assistant Chief Counsel, Attention: Rules Docket No. 97-ANE-25-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: "9-ad-engineprop@faa.dot.gov". Comments sent via the Internet must contain the docket number in the subject line.
The service information referenced in this AD may be obtained from Pratt & Whitney, 400
Main St., East Hartford, CT 06108; telephone (860) 565-6600, fax (860) 565-4503. This information may be examined at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

John Fisher, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (617) 238-7149, fax (617) 238-7199.