[Federal Register Volume 63, Number 251 (Thursday, December 31, 1998)]
[Rules and Regulations]
[Pages 72148-72154]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-34706]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-ANE-77-AD; Amendment 39-10975; AD 99-01-08]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney JT8D and JT3D Series
Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
-----------------------------------------------------------------------
SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to Pratt & Whitney (PW) JT8D and JT3D series turbofan
engines. This action requires operators to remove and replace with
serviceable parts, certain stage 7 through stage 15 high-pressure
compressor (HPC) disks identified by part number and serial number.
This amendment is prompted by a report of an uncontained failure of a
stage 8 HPC disk during a takeoff roll that resulted in damage to the
airplane. The actions specified in this AD are intended to prevent the
failure of a high-pressure compressor disk due to Cadmium
embrittlement, resulting in uncontained engine failure and damage to
the airplane.
DATES: Effective January 5, 1999.
Comments for inclusion in the Rules Docket must be received on or
before March 1, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Regional
Counsel, Attention: Rules Docket No. 98-ANE-77-AD, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may also be sent
via the Internet using the following address: ``9-ad-
[email protected]''. 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 Regional Counsel, Burlington,
MA.
FOR FURTHER INFORMATION CONTACT: Christopher Spinney, Aerospace
Engineer, Engine Certification Office, FAA, Engine and Propeller
Directorate, 12 New England Executive Park, Burlington, MA 01803-5299;
telephone (781) 238-7175, fax (781) 238-7199.
SUPPLEMENTARY INFORMATION: The Federal Aviation Administration (FAA)
has received a report of an uncontained failure of a stage 8 high-
pressure compressor (HPC) disk, part number (P/N) 787008, installed on
a Pratt & Whitney (PW) JT8D-9 turbofan engine. The laboratory testing
revealed that the disk failed as a result of Cadmium embrittlement.
Nickel-Cadmium (NiCd) coatings are used on JT8D and JT3D steel disks to
inhibit corrosion. The coating process consists of many steps, the most
fundamental of which are the electrolytic deposition of a Nickel base
layer followed eventually by the electrolytic deposition of a Cadmium
layer. The part is then baked in an oven. During the bake cycle the
Nickel layer diffuses into the Cadmium which creates an alloy with a
higher melting temperature than pure Cadmium and immobilizes the
Cadmium to prevent the liquid metal embrittlement of the steel part.
The Cadmium rich outer layer acts as the corrosion inhibitor. The
diffused Nickel acts to immobilize the Cadmium and prevent Cadmium
embrittlement of the steel. If the Nickel plating is not applied with
sufficient thickness during the NiCd plating process, the undiffused
Cadmium can attack the grain boundaries of the base metal. Failure
results when the disk is exposed to engine operating temperatures and
stresses. Analysis of this and other Cadmium embrittlement failures
indicates that a disk exposed to Cadmium embrittlement will likely fail
within 500 hours time-in-service (TIS). Based on the risks associated
with a process anomaly at the repair facility that plated the disk, the
FAA has determined that action is required to remove a number of disks
plated at that facility since February 1996. The disks most at risk are
those disks which have accumulated less than 500 hours TIS since they
were last plated. Disks which have accumulated more than 500 hours TIS
since plating will not be recalled by this AD. The FAA has identified
stage 7 through stage 15 HPC disks by P/N and serial number (S/N) that
have been NiCd plated by the repair facility from February 1996 through
October 1998. This condition, if not corrected, could result in the
failure of a high-pressure compressor disk due to Cadmium
embrittlement, resulting in uncontained engine failure and damage to
the airplane.
Since an unsafe condition has been identified that is likely to
exist or develop on other engines of the same type design, this AD is
being issued to prevent the failure of a high-pressure compressor disk
due to Cadmium embrittlement, resulting in uncontained engine failure
and damage to the airplane. This AD requires removal and replacement of
certain part-numbered and serial-numbered stage 7 through stage 15 HPC
disks with serviceable parts.
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.
[[Page 72149]]
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 aspects of 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 98-ANE-77-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, 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.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
99-01-08 Pratt & Whitney: Amendment 39-10975. Docket 98-ANE-77-AD.
Applicability: Pratt & Whitney (PW) JT8D and JT3D series
turbofan engines, with stage 7 through stage 15 high-pressure
compressor (HPC) disks installed, identified by part number (P/N)
and serial number (S/N) specified in Appendix 1. These engines are
installed on but not limited to the following aircraft: Boeing 707,
727, and 737 series airplanes and McDonnell Douglas DC-8, DC-9, and
MD-80 series airplanes.
Appendix 1
Disk Part Number and Serial Number (Sorted by Disk Part Number)
------------------------------------------------------------------------
Stage Disk part No. Disk serial No.
------------------------------------------------------------------------
7................................ 701407 7A7271
7................................ 701507 4Z2030
7................................ 701507 4Z2122
7................................ 701507 8Z6454
7................................ 766007 8B5265
7................................ 774407 B207AA0307
7................................ 774407 B207AA0350
7................................ 774407 B207AA0379
7................................ 774407 B207AA0578
7................................ 774407 B207AA0643
7................................ 774407 BENCAH1353
7................................ 774407 BENCAH2320
7................................ 774407 BENCAH2327
7................................ 774407 BENCAH2851
7................................ 774407 BENCAH4091
7................................ 774407 BENCAJ8414
7................................ 774407 BENCAJ8440
7................................ 774407 BENCAK1631
7................................ 774407 BENCAK1684
7................................ 774407 BENCAK5135
7................................ 774407 BENCAK6623
7................................ 774407 BENCAK6643
7................................ 774407 BENCAK8115
7................................ 774407 H19093
7................................ 774407 H19026
7................................ 774407 H29904
7................................ 774407 J17128
7................................ 774407 J17407
7................................ 774407 J39120
7................................ 774407 J72011
7................................ 774407 J72132
7................................ 774407 K20050
7................................ 774407 K20167
7................................ 774407 K78491
7................................ 774407 L72139
7................................ 774407 M15364
7................................ 774407 M15368
7................................ 774407 M77985
7................................ 774407 M83784
7................................ 774407 M93463
7................................ 774407 N14127
7................................ 774407 N14190
7................................ 774407 N14213
7................................ 774407 N24114
7................................ 774407 N23978
7................................ 774407 N24091
7................................ 774407 N37879
7................................ 774407 N37919
7................................ 774407 N70390
7................................ 774407 N88161
7................................ 774407 N88195
7................................ 774407 N88335
7................................ 774407 N88342
7................................ 774407 N94974
7................................ 774407 N95036
7................................ 774407 P14716
7................................ 774407 P14741
7................................ 774407 P35486
7................................ 774407 P54563
7................................ 774407 P60347
7................................ 774407 P60394
7................................ 774407 P60446
7................................ 774407 P70328
7................................ 774407 P81247
7................................ 774407 P81253
7................................ 774407 P81392
7................................ 774407 P81399
7................................ 774407 P86295
7................................ 774407 P86311
7................................ 774407 R03089
7................................ 774407 R12413
7................................ 774407 R12418
7................................ 774407 R12549
7................................ 774407 R12557
7................................ 774407 R19365
7................................ 774407 R31290
7................................ 774407 R31411
7................................ 774407 R37414
7................................ 774407 R37520
7................................ 774407 R37554
7................................ 774407 R46834
7................................ 774407 R46893
7................................ 774407 R46918
7................................ 774407 R46943
7................................ 774407 R47019
7................................ 774407 R72171
[[Page 72150]]
7................................ 774407 R72257
7................................ 774407 S05566
7................................ 774407 S05610
7................................ 774407 S05659
7................................ 774407 S10014
7................................ 774407 S10050
7................................ 774407 S13885
7................................ 774407 S13910
7................................ 774407 S14048
7................................ 774407 S14063
7................................ 774407 S14088
7................................ 774407 S14173
7................................ 774407 S36633
7................................ 774407 S36810
7................................ 774407 S36857
7................................ 774407 S37128
7................................ 774407 S37149
7................................ 774407 S37168
7................................ 774407 S37187
7................................ 774407 S37312
7................................ 774407 S37367
7................................ 774407 S37389
7................................ 774407 S37420
7................................ 774407 S37469
7................................ 774407 S37498
7................................ 774407 T04409
7................................ 774407 T04526
7................................ 774407 T04566
7................................ 774407 T04615
7................................ 774407 T04632
7................................ 774407 T04898
7................................ 774407 T04899
7................................ 774407 T04988
7................................ 774407 T05055
7................................ 774407 T05106
7................................ 5006007-01 B207AA0068
7................................ 5006007-01 B207AA0693
7................................ 5006007-01 BENCAH0061
7................................ 5006007-01 BENCAH3134
7................................ 5006007-01 BENCAJ8558
7................................ 5006007-01 BENCAJ8594
7................................ 5006007-01 BENCAL0749
7................................ 5006007-01 BENCAL2650
7................................ 5006007-01 R54586
7................................ 5006007-01 R79450
7................................ 5006007-01 S11202
7................................ 5006007-01 S11206
7................................ 5006007-01 S57118
7................................ 5006007-01 S57216
7................................ 5006007-01 S57519
7................................ 5006007-02 BENCAK9643
7................................ 5006007-02 BENCAK9690
7................................ 5006007-02 BENCAK9697
7................................ 5006007-02 BENCAK9705
7................................ 5006007-02 BENCAK9723
7................................ 5006007-02 BENCAL3657
7................................ 5006007-02 BENCAL5478
7................................ 774407 BENCAH0521
7................................ 774407 BENCAJ8454
7................................ 774407 R57626
7................................ 774407 T04885
8................................ 738308 9B1363
8................................ 738308 H03990
8................................ 748608 7A9608
8................................ 748608 7B9489
8................................ 748608 8B0397
8................................ 748608 B208AA0030
8................................ 748608 B208AA0045
8................................ 748608 B208AA0070
8................................ 748608 BENCAJ8185
8................................ 748608 G30014
8................................ 748608 G62624
8................................ 748608 G63907
8................................ 748608 H29599
8................................ 748608 H35085
8................................ 748608 H64390
8................................ 748608 H84992
8................................ 748608 H86520
8................................ 748608 J29857
8................................ 748608 J29958
8................................ 748608 J57418
8................................ 748608 J57426
8................................ 748608 J57469
8................................ 748608 J57532
8................................ 748608 J57660
8................................ 748608 J57663
8................................ 748608 J94763
8................................ 748608 J94815
8................................ 748608 M54646
8................................ 748608 M54770
8................................ 748608 M54821
8................................ 748608 M54843
8................................ 748608 N14562
8................................ 748608 N14765
8................................ 748608 N84308
8................................ 748608 N84314
8................................ 748608 N84317
8................................ 748608 N84319
8................................ 748608 N84373
8................................ 748608 N84418
8................................ 748608 P26025
8................................ 748608 P26136
8................................ 748608 P26153
8................................ 748608 P26171
8................................ 748608 P28471
8................................ 748608 P28530
8................................ 748608 P28534
8................................ 748608 P28564
8................................ 748608 P28596
8................................ 748608 P28607
8................................ 748608 P83853
8................................ 748608 P94736
8................................ 748608 P98927
8................................ 748608 R18995
8................................ 748608 R46153
8................................ 748608 R73850
8................................ 748608 S01136
8................................ 748608 S01153
8................................ 748608 S01185
8................................ 748608 S50692
8................................ 748608 S50748
8................................ 748608 S78016
8................................ 748608 S78066
8................................ 748608 S78128
8................................ 787008 K51696
8................................ 787008 K52389
8................................ 787008 L61543
8................................ 787008 M76852
8................................ 787008 M77423
8................................ 787008 M77749
8................................ 787008 M77791
8................................ 787008 N33354
8................................ 787008 N33408
8................................ 787008 N33702
8................................ 787008 N33760
8................................ 787008 N89060
8................................ 787008 N89386
8................................ 787008 N90133
8................................ 787008 N90152
8................................ 787008F N89050
8................................ 787208 B228AA0194
8................................ 787208 B228AA0343
8................................ 787208 B228AA0371
8................................ 787208 B228AA0540
8................................ 787208 B228AA0574
8................................ 787208 B228AA0605
8................................ 787208 BENCAH4505
8................................ 787208 BENCAH5428
8................................ 787208 BENCAH5435
8................................ 787208 BENCAJ5724
8................................ 787208 BENCAK0065
8................................ 787208 BENCAK0066
8................................ 787208 BENCAK6165
8................................ 787208 BENCAK6359
8................................ 787208 BENCAK8796
8................................ 787208 BENCAK9253
8................................ 787208 BENCAL1567
8................................ 787208 BENCAL1571
8................................ 787208 BENCAL1579
8................................ 787208 BENCAL1887
8................................ 787208 BENCAL3339
8................................ 787208 BENCAL5283
8................................ 787208 BENCAM0672
8................................ 787208 J47026
8................................ 787208 K12730
8................................ 787208 N06609
8................................ 787208 N89709
8................................ 787208 P43644
8................................ 787208 P43665
8................................ 787208 P43897
8................................ 787208 P43936
8................................ 787208 P43950
8................................ 787208 P43954
8................................ 787208 P44141
8................................ 787208 P44694
8................................ 787208 P45378
8................................ 787208 P45593
8................................ 787208 R23192
8................................ 787208 R23234
8................................ 787208 R23450
8................................ 787208 R23452
8................................ 787208 R23569
8................................ 787208 R23837
8................................ 787208 R24172
8................................ 787208 R24201
8................................ 787208 R24205
8................................ 787208 R24390
8................................ 787208 R24599
8................................ 787208 R24827
8................................ 787208 R91709
8................................ 787208 S07732
8................................ 787208 S39110
8................................ 787208 S39281
8................................ 787208 S39337
8................................ 787208 S39409
8................................ 787208 S39410
8................................ 787208 S39487
8................................ 787208 S39509
8................................ 787208 S39534
8................................ 787208 S39633
8................................ 787208 S39676
8................................ 787208 S39721
8................................ 787208 S39942
8................................ 787208 S39963
8................................ 787208 S39996
8................................ 787208 S40033
8................................ 787208 S40041
[[Page 72151]]
8................................ 788608 H36177
8................................ 788708 7A2254
8................................ 789508 G51990
8................................ 789608 J46995
8................................ 792038 B228AA0331
8................................ 792038 B228AA0511
8................................ 792038 B228AA1005
8................................ 792038 BENCAJ8854
8................................ 792038 BENCAJ8871
8................................ 796348 K53240
8................................ 797938 BENCAL2605
8................................ 5005808-01 B228AA0901
8................................ 5005808-01 BENCAJ1138
8................................ 5005808-01 BENCAJ8902
8................................ 5005808-01 S70327
9................................ 628209 5X8746
9................................ 701509 8Z5256
9................................ 701509 9A6145
9................................ 701509 H86825
9................................ 701509 J00245
9................................ 701509 J25666
9................................ 701509 J87515
9................................ 701509 J89031
9................................ 701509 K34309
9................................ 701509 K35061
9................................ 701509 K55559
9................................ 701509 K85824
9................................ 701509 L31209
9................................ 701509 L31751
9................................ 701509 L55770
9................................ 701509 M10469
9................................ 701509 M40027
9................................ 701509 M49712
9................................ 701509 M61566
9................................ 701509 M84762
9................................ 701509 M86342
9................................ 701509 M86842
9................................ 701509 M86844
9................................ 701509 N02758
9................................ 701509 N02994
9................................ 701509 N209AA0006
9................................ 701509 N209AA0080
9................................ 701509 N209AA0091
9................................ 701509 N209AA0094
9................................ 701509 N209AA0255
9................................ 701509 N209AA0339
9................................ 701509 N209AA0352
9................................ 701509 N209AA0561
9................................ 701509 N21068
9................................ 701509 N21507
9................................ 701509 N21508
9................................ 701509 N22475
9................................ 701509 N22570
9................................ 701509 N22591
9................................ 701509 N41297
9................................ 701509 N42662
9................................ 701509 N57120
9................................ 701509 N79874
9................................ 701509 N79893
9................................ 701509 N81317
9................................ 701509 N97653
9................................ 701509 NENCAH0017
9................................ 701509 NENCAH0187
9................................ 701509 NENCAH0192
9................................ 701509 NENCAH0222
9................................ 701509 NENCAH0269
9................................ 701509 NENCAH0280
9................................ 701509 NENCAH0337
9................................ 701509 NENCAH0422
9................................ 701509 NENCAH0445
9................................ 701509 NENCAH0451
9................................ 701509 NENCAH0593
9................................ 701509 NENCAH0737
9................................ 701509 NENCAH0757
9................................ 701509 NENCAH0913
9................................ 701509 NENCAH0920
9................................ 701509 NENCAH1014
9................................ 701509 NENCAH1227
9................................ 701509 NENCAH1357
9................................ 701509 NENCAH1430
9................................ 701509 P11360
9................................ 701509 P11370
9................................ 701509 P11443
9................................ 701509 P11450
9................................ 701509 P12878
9................................ 701509 P51572
9................................ 701509 P52444
9................................ 701509 P52971
9................................ 701509 P53248
9................................ 701509 P77028
9................................ 701509 P77207
9................................ 701509 P78457
9................................ 701509 P97645
9................................ 701509 P98143
9................................ 701509 P98661
9................................ 701509 P98961
9................................ 701509 P98991
9................................ 701509 R17442
9................................ 701509 R18113
9................................ 701509 R45676
9................................ 701509 R46466
9................................ 701509 R72941
9................................ 701509 R73009
9................................ 701509 R73013
9................................ 701509 R73420
9................................ 701509 R73464
9................................ 701509 R73467
9................................ 701509 R73804
9................................ 701509 R73934
9................................ 701509 S00689
9................................ 701509 S00741
9................................ 701509 S00777
9................................ 701509 S00798
9................................ 701509 S18975
9................................ 701509 S19201
9................................ 701509 S50490
9................................ 701509 S77602
9................................ 701509 S77616
9................................ 701509 S77651
9................................ 739509 G79836
9................................ 772509 H49185
9................................ 772509 K56788
9................................ 772509 P97497
9................................ 772509 R73983
9................................ 772509 S01209
9................................ 772509 S50832
9................................ 798509 B209AA0539
9................................ 798509 BENCAH3770
9................................ 798509 BENCAJ9383
9................................ 798509 BENCAK9880
9................................ 798509 BENCAL0717
9................................ 798509 BENCAL0703
9................................ 798509 BENCAL2372
9................................ 798509 BENCAL6305
9................................ 701509 BENCAH0448
9................................ 701509N R18236
9................................ 772509 K23767
9................................ 798509 BENCAJ9360
9................................ 798509 P53159
10............................... 701410 7Z0800
10............................... 701410 7Z0806
10............................... 701810 0A0377
10............................... 701810 3B8966
10............................... 701810 3B9144
10............................... 701810 9Z9847
10............................... 701810 A00862
10............................... 701810 H39339
10............................... 701810 H60642
10............................... 701810 R22292
10............................... 701810G G82663
10............................... 770510 4B4921
10............................... 770510 G80187
10............................... 772510 B210AA0014
10............................... 772510 B210AA0202
10............................... 772510 B210AA0273
10............................... 772510 B210AA0637
10............................... 772510 B210AA0640
10............................... 772510 B210AA0749
10............................... 772510 B210AA0752
10............................... 772510 B210AA0429
10............................... 772510 BENCAH0251
10............................... 772510 BENCAH1404
10............................... 772510 BENCAJ9735
10............................... 772510 BENCAJ9784
10............................... 772510 BENCAJ9868
10............................... 772510 BENCAK5318
10............................... 772510 BENCAK5762
10............................... 772510 BENCAK5946
10............................... 772510 BENCAK9105
10............................... 772510 BENCAL0388
10............................... 772510 BENCAL1598
10............................... 772510 BENCAL1601
10............................... 772510 BENCAL2427
10............................... 772510 BENCAL4455
10............................... 772510 BENCAL5993
10............................... 772510 H34395
10............................... 772510 H58784
10............................... 772510 J23708
10............................... 772510 J68609
10............................... 772510 J87953
10............................... 772510 J88767
10............................... 772510 K03190
10............................... 772510 K03586
10............................... 772510 K24796
10............................... 772510 K25271
10............................... 772510 K35625
10............................... 772510 K55848
10............................... 772510 K66100
10............................... 772510 K68068
10............................... 772510 K85468
10............................... 772510 L15000
10............................... 772510 L56873
10............................... 772510 L84428
10............................... 772510 L86007
10............................... 772510 M10049
10............................... 772510 M10613
10............................... 772510 M39974
10............................... 772510 M56263
10............................... 772510 M61659
10............................... 772510 M84606
10............................... 772510 M87097
10............................... 772510 N03907
10............................... 772510 N02538
10............................... 772510 N02778
10............................... 772510 N03133
10............................... 772510 N21767
10............................... 772510 N22275
[[Page 72152]]
10............................... 772510 N41185
10............................... 772510 N41208
10............................... 772510 N41484
10............................... 772510 N41613
10............................... 772510 N42094
10............................... 772510 N42143
10............................... 772510 N42187
10............................... 772510 N42838
10............................... 772510 N57150
10............................... 772510 N57830
10............................... 772510 N57862
10............................... 772510 N80227
10............................... 772510 N80661
10............................... 772510 N80671
10............................... 772510 N81136
10............................... 772510 N81150
10............................... 772510 N81454
10............................... 772510 N81456
10............................... 772510 P11024
10............................... 772510 P11818
10............................... 772510 P11869
10............................... 772510 P12016
10............................... 772510 P12811
10............................... 772510 P51804
10............................... 772510 P51873
10............................... 772510 P52670
10............................... 772510 P53019
10............................... 772510 P53213
10............................... 772510 P76639
10............................... 772510 P77620
10............................... 772510 P77862
10............................... 772510 P78050
10............................... 772510 P97278
10............................... 772510 P98630
10............................... 772510 R17507
10............................... 772510 R18502
10............................... 772510 R18520
10............................... 772510 R44856
10............................... 772510 R44861
10............................... 772510 R44864
10............................... 772510 R45159
10............................... 772510 R46345
10............................... 772510 R72614
10............................... 772510 R72630
10............................... 772510 R72884
10............................... 772510 R73138
10............................... 772510 R73408
10............................... 772510 R73612
10............................... 772510 R73617
10............................... 772510 R73862
10............................... 772510 S01349
10............................... 772510 S01364
10............................... 772510 S01365
10............................... 772510 S01406
10............................... 772510 S01463
10............................... 772510 S01486
10............................... 772510 S19301
10............................... 772510 S19305
10............................... 772510 S19487
10............................... 772510 S19630
10............................... 772510 S50981
10............................... 772510 S51203
10............................... 772510 S70220
10............................... 772510 S78451
10............................... 772510 S78492
10............................... 772510 S78780
10............................... 772510 T18947
10............................... 772510 T19138
10............................... 772510 T19153
10............................... 772510 T49020
10............................... 772510 BENCAJ9732
10............................... 772510 N81125
10............................... 772510 S70249
11............................... 701411 2B3335
11............................... 701411 6Y6265
11............................... 701411 6Y7124
11............................... 701411 9Y4723
11............................... 701811 A03782
11............................... 701811 G33309
11............................... 701811 H24029
11............................... 701811 J28340
11............................... 701811D 5A8129
11............................... 772511 B211AA0058
11............................... 772511 B211AA0106
11............................... 772511 B211AA0119
11............................... 772511 B211AA0240
11............................... 772511 B211AA0621
11............................... 772511 B211AA0744
11............................... 772511 B211AA0944
11............................... 772511 B211AA1224
11............................... 772511 B211AA1227
11............................... 772511 BENCAH4040
11............................... 772511 BENCAK0466
11............................... 772511 BENCAK7376
11............................... 772511 BENCAK7377
11............................... 772511 BENCAK7378
11............................... 772511 BENCAK7391
11............................... 772511 BENCAK7432
11............................... 772511 BENCAK7436
11............................... 772511 BENCAK7449
11............................... 772511 BENCAK7493
11............................... 772511 BENCAK7517
11............................... 772511 BENCAL2882
11............................... 772511 BENCAL2903
11............................... 772511 BENCAL3047
11............................... 772511 BENCAL3107
11............................... 772511 J23871
11............................... 772511 J60159
11............................... 772511 J60844
11............................... 772511 J88645
11............................... 772511 K23851
11............................... 772511 K25421
11............................... 772511 K34786
11............................... 772511 K35678
11............................... 772511 K56219
11............................... 772511 K86641
11............................... 772511 L30533
11............................... 772511 L31909
11............................... 772511 L84584
11............................... 772511 L85406
11............................... 772511 LI4848
11............................... 772511 M39922
11............................... 772511 M40288
11............................... 772511 M49491
11............................... 772511 M61348
11............................... 772511 M73855
11............................... 772511 M86390
11............................... 772511 N21317
11............................... 772511 N02565
11............................... 772511 N02849
11............................... 772511 N03254
11............................... 772511 N03566
11............................... 772511 N03749
11............................... 772511 N03884
11............................... 772511 N21373
11............................... 772511 N21747
11............................... 772511 N22005
11............................... 772511 N22023
11............................... 772511 N22361
11............................... 772511 N22749
11............................... 772511 N41265
11............................... 772511 N41900
11............................... 772511 N42762
11............................... 772511 N56596
11............................... 772511 N57211
11............................... 772511 N57249
11............................... 772511 N57915
11............................... 772511 N98569
11............................... 772511 N98918
11............................... 772511 N99538
11............................... 772511 P10980
11............................... 772511 P11984
11............................... 772511 P12374
11............................... 772511 P12389
11............................... 772511 P12900
11............................... 772511 P51911
11............................... 772511 P52733
11............................... 772511 P53057
11............................... 772511 P66436
11............................... 772511 P77051
11............................... 772511 P77157
11............................... 772511 P77977
11............................... 772511 P78064
11............................... 772511 P78528
11............................... 772511 P78566
11............................... 772511 R05712
11............................... 772511 R18713
11............................... 772511 R29689
11............................... 772511 R29849
11............................... 772511 R29855
11............................... 772511 R29858
11............................... 772511 R29957
11............................... 772511 R30079
11............................... 772511 R30091
11............................... 772511 R30098
11............................... 772511 R30396
11............................... 772511 R30540
11............................... 772511 R30753
11............................... 772511 R30778
11............................... 772511 R31032
11............................... 772511 R44897
11............................... 772511 R45822
11............................... 772511 R46094
11............................... 772511 R46488
11............................... 772511 S03919
11............................... 772511 S03920
11............................... 772511 S04110
11............................... 772511 S04209
11............................... 772511 S04340
11............................... 772511 S04487
11............................... 772511 S04565
11............................... 772511 S04576
11............................... 772511 S04601
11............................... 772511 S04625
11............................... 772511 S80671
11............................... 772511 S80726
11............................... 772511 S80801
11............................... 772511 S80817
11............................... 772511 S80830
11............................... 772511 T22255
11............................... 772511 T22427
11............................... 772511 T22430
11............................... 772511 T22433
11............................... 772511 T22695
11............................... 772511 T22711
11............................... 772511 T23028
11............................... 772511 B211AA0681
[[Page 72153]]
11............................... 772511 N97343
11............................... 772511H S03892
11............................... 772511M B211AA0066
11............................... 772511M B211AA0584
12............................... 414212HC 5L5355
12............................... 701412 1Z5717
12............................... 701412 5Y5915
12............................... 701812 1Z7175
12............................... 701812 3A3910
12............................... 701812 A02080
12............................... 701812 H62635
12............................... 701812 N28026
12............................... 701812D G93483
12............................... 717312 2B3418
12............................... 717312 G15036
12............................... 717312 G29488
12............................... 717312 G63557
12............................... 769312 1Z5153
12............................... 772512 H34015
12............................... 772512 H77074
12............................... 772512 J24654
12............................... 772512 J38490
12............................... 772512 J59514
12............................... 772512 K02314
12............................... 772512 K24837
12............................... 772512 K55637
12............................... 772512 K55648
12............................... 772512 K86189
12............................... 772512 L15523
12............................... 772512 L30268
12............................... 772512 L30307
12............................... 772512 L31553
12............................... 772512 L56280
12............................... 772512 L56328
12............................... 772512 L84937
12............................... 772512 L86244
12............................... 772512 M86432
12............................... 772512 M10163
12............................... 772512 M10415
12............................... 772512 M10948
12............................... 772512 M11260
12............................... 772512 M11282
12............................... 772512 M40263
12............................... 772512 M48887
12............................... 772512 M49046
12............................... 772512 M49595
12............................... 772512 M61285
12............................... 772512 M61856
12............................... 772512 M61955
12............................... 772512 M84903
12............................... 772512 M86222
12............................... 772512 N02391
12............................... 772512 N02431
12............................... 772512 N02488
12............................... 772512 N03222
12............................... 772512 N03686
12............................... 772512 N22344
12............................... 772512 N22883
12............................... 772512 N41245
12............................... 772512 N41249
12............................... 772512 N41463
12............................... 772512 N57445
12............................... 772512 N57460
12............................... 772512 N58065
12............................... 772512 N58102
12............................... 772512 N58109
12............................... 772512 N58117
12............................... 772512 N80256
12............................... 772512 N81365
12............................... 772512 N97115
12............................... 772512 N97124
12............................... 772512 N97457
12............................... 772512 N98208
12............................... 772512 N98222
12............................... 772512 N99001
12............................... 772512 N99066
12............................... 772512 P11199
12............................... 772512 P12270
12............................... 772512 P12312
12............................... 772512 P51405
12............................... 772512 P51433
12............................... 772512 P51437
12............................... 772512 P52633
12............................... 772512 P53139
12............................... 772512 P53173
12............................... 772512 P77109
12............................... 772512 P77978
12............................... 772512 P78005
12............................... 772512 P78202
12............................... 772512 P97472
12............................... 772512 P98163
12............................... 772512 P98509
12............................... 772512 P98706
12............................... 772512 P98876
12............................... 772512 R17547
12............................... 772512 R18000
12............................... 772512 R18009
12............................... 772512 R18395
12............................... 772512 R18404
12............................... 772512 R19046
12............................... 772512 R19047
12............................... 772512 R45120
12............................... 772512 R45947
12............................... 772512 R46042
12............................... 772512 R46055
12............................... 772512 R73153
12............................... 772512 R73459
12............................... 772512 R73782
12............................... 772512 R74102
12............................... 772512 R74120
12............................... 772512 R74356
12............................... 772512 R74528
12............................... 772512 S01701
12............................... 772512 S01720
12............................... 772512 S01963
12............................... 772512 S02019
12............................... 772512 S51348
12............................... 772512 S51376
12............................... 772512 S51391
12............................... 772512 S51490
12............................... 772512 S51499
12............................... 772512 S51540
12............................... 772512 S51542
12............................... 772512 S78919
12............................... 772512 S78924
12............................... 798512 B212AA0948
12............................... 798512 B212AA0032
12............................... 798512 B212AA0209
12............................... 798512 B212AA0234
12............................... 798512 B212AA0255
12............................... 798512 B212AA0276
12............................... 798512 B212AA0283
12............................... 798512 B212AA0436
12............................... 798512 B212AA0439
12............................... 798512 B212AA0442
12............................... 798512 B212AA0497
12............................... 798512 B212AA0739
12............................... 798512 B212AA0788
12............................... 798512 B212AA0808
12............................... 798512 B212AA0826
12............................... 798512 B212AA1042
12............................... 798512 BENCAH1745
12............................... 798512 BENCAH2182
12............................... 798512 BENCAJ9560
12............................... 798512 BENCAJ9619
12............................... 798512 BENCAJ9680
12............................... 798512 BENCAK8619
12............................... 798512 BENCAK9455
12............................... 798512 BENCAL0437
12............................... 798512 BENCAL0445
12............................... 798512 BENCAL0446
12............................... 798512 BENCAL0450
12............................... 798512 BENCAL2451
12............................... 798512 BENCAL2462
12............................... 798512 BENCAL5111
12............................... 798512 BENCAL6030
12............................... 798512 R46125
12............................... 798512 S94444
12............................... 798512 S94463
12............................... 798512 S94550
12............................... 798512 T19384
12............................... 798512 T28481
12............................... 798512 T28560
12............................... 798512 T28581
12............................... 798512 T43085
12............................... 772512 N97437
12............................... 772512G S02004
12............................... 798512 BENCAJ9509
12............................... 798512 BENCAL2313
12............................... 798512 BENCAL6575
13............................... 701813 9B6665
13............................... 701813 G92924
13............................... 701813 H10764
13............................... 701813 H63434
13............................... 701813 H63596
13............................... 701813E H40915
13............................... 762413 T02660
14............................... 750414 H91643
14............................... 750414 H92945
14............................... 750414 N68876
14............................... 750414 P95479
14............................... 750414 T39660
15............................... 750115 H530181
15............................... 750415 J35404
15............................... 750415 S97819
------------------------------------------------------------------------
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 (b) of this AD. The request should include an assessment
of the effect of the modification, alteration, or repair on the
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.
[[Page 72154]]
To prevent the failure of a high-pressure compressor disk due to
Cadmium embrittlement, resulting in uncontained engine failure and
damage to the airplane, accomplish the following:
(a) Remove from service stage 7 through stage 15 high-pressure
compressor (HPC) disks identified in Appendix 1 of this AD as
follows:
(1) For disks with less than 250 hours time in service (TIS)
since last NiCd plating, remove disk and replace with a serviceable
part within 100 hours TIS after the effective date of this AD.
(2) For disks with greater than or equal to 250 hours and less
than 500 hours TIS since last NiCd plating, remove disk and replace
with a serviceable part within 150 hours TIS after the effective
date of this AD.
(3) For disks with greater than or equal to 500 hours TIS since
last NiCd plating no action is required.
(4) Disks removed from service in accordance with this AD are
not eligible for installation in any engine.
(b) 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 2: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the Engine Certification Office.
(c) 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 record search requirements of this AD can be accomplished.
(d) This amendment becomes effective on January 5, 1999.
Issued in Burlington, Massachusetts, on December 23, 1998.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 98-34706 Filed 12-30-98; 8:45 am]
BILLING CODE 4910-13-P