AD 97-17-04

This amendment supersedes an existing airworthiness directive (AD), applicable to Pratt & Whitney JT8D-200 series turbofan engines, that currently requires cleaning of front compressor front hubs (fan hubs); initial and repetitive eddy current (ECI) and fluorescent penetrant inspections (FPI) of tierod and counterweight holes for cracks; removal of bushings; the cleaning and ECI and FPI of bushed holes for cracks; and, if necessary, replacement with serviceable parts. In addition, the current AD requires reporting the findings of cracked fan hubs. This amendment does not change the current AD's inspection procedures, or the effectivity date that starts the cycle count for the initial inspection schedules. This AD does, however, add an additional inspection schedule that requires the initial inspection of certain fan hubs with standard drilled holes and coolant channel drilled (CCD) holes to occur earlier than the existing AD requires. Also, this AD requires reporting the results of the initial fan hub inspections. This amendment is prompted by additional investigation since publication of the current AD that reveals that certain fan hubs with standard drilled holes and CCD holes may be more susceptible to cracking. The actions specified by this AD are intended to prevent fan hub failure due to tierod, counterweight, or bushed hole cracking, which could result in an uncontained engine failure and damage to the aircraft.

Final rule.

97-17-04 Pratt & Whitney: Amendment 39-10106. Docket 97-ANE-08. Supersedes AD 97-02-11, Amendment 39-9896.
Applicability: Pratt & Whitney JT8D-209, -217, -217C, and -219 series turbofan engines with front compressor front hub (fan hub), Part Number (P/N) 5000501-01, installed. These engines are installed on but not limited to McDonnell Douglas MD-80 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 (c) 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.
To prevent fan hub failure due to tierod, counterweight, or bushed hole cracking, which could result in an uncontained engine failure and damage to the aircraft, accomplish the following:
(a) Inspect fan hubs for cracks in accordance with the Accomplishment Instructions, Paragraph A, Part 1, and, if applicable, Paragraph B, of PW ASB No. A6272, dated September 24, 1996, as follows:
(1) For fan hubs identified by Serial Numbers (S/Ns) in Table 2 of this AD, after the fan hub has accumulated more than 4,000 cycles since new (CSN), as follows:
(i) Initially inspect within 315 cycles in service (CIS) from the effective date of this AD, or 4,315 CSN, whichever occurs later.
(ii) Thereafter, reinspect after accumulating 2,500 CIS since last inspection, but not to exceed 10,000 CIS since last inspection.
(2) For fan hubs identified by S/Ns in Appendix A of PW ASB No. A6272, dated September 24, 1996, after the fan hub has accumulated more than 4,000 CSN, as follows:
(i) Select an initial inspection interval from Table 1 of this AD, and inspect accordingly.

Table 1

Initial Inspection
Reinspection
1. Within 1,050 cycles in service (CIS) after the effective date of AD 97-02-11, March 5, 1997, or prior to accumulating 5,050 CSN, whichever occurs later;
After accumulating 2,500 CIS since last inspection, but not to exceed 6,000 CIS since last inspection.

OR
OR
2. Within 990 CIS after the effective date of AD 97-02-11, March 5, 1997, or prior to accumulating 4,990 CSN, whichever occurs later;
After accumulating 2,500 CIS since last inspection, but not to exceed 8,000 CIS since last inspection.
OR
OR
3. Within 965 CIS after the effective date of AD 97-02-11, March 5, 1997, or prior to accumu- lating 4,965 CSN, whichever occurs later.
After accumulating 2,500 CIS since last inspection, but not to exceed 10,000 CIS since last inspection.

Table 2
Hubs with traveler notations

Non CCD
Non CCD
Non CCD
Non CCD
CCD Hub
CCD Hub
CCD Hub
M67663
M67802
P66880
S25545
P66747
R33099
S25292
M67671
M67812
P66885
S25558
P66756
R33107
S25299
M67675
M67826
R32732
S25564
P66800
R33113
S25301
M67681
M67829
R32733
S25598
P66814
R33124
S25302
M67685
M67830
R32735
S25618
P66819
R33131
S25308
M67686
M67831
R32740
S25621
P66831
R33132
S25312
M67687
M67832
R32741
S25637
R32767
R33133
S25316
M67697
M67834
R32810
S25640
R32787
R33136
S25323
M67700
M67843
R32849
T50693
R32792
R33152
S25334
M67706
M67849
R32850
T50752
R32795
R33157
S25335
M67710
M67858
S25222
T50785
R32796
R33163
S25337
M67712
M67866
S25464
T50791
R32800
R33165
S25344
M67713
M67868
S25481
T50792
R32807
R33168
S25369
M67714
M67869
S25483
T50819
R32856
R33171
S25377
M67715
M67872
S25484
T50823
R32860
R33173
S25378
M67716
M67888
S25486
T50827
R32870
R33180
S25381
M67717
N71771
S25488
T50874
R32883
R33181
S25394
M67722
N71804
S25489
T50875
R32905
R33189
S25399
M67723
N71806
S25490
T51058
R32926
R33194
S25402
M67725
N71810
S25491
T51104
R32930
R33198
S25406
M67726
N71811
S25492

R32952
R33201
S25411
M67730
N71875
S25494

R32964
R33202
S25413
M67731
N71876
S25495

R32966
R33207
S25414
M67746
N71921
S25497

R32971
S25193
S25415
M67751
N71965
S25498

R32976
S25195
S25418
M67753
N72062
S25499

R32981
S25207
S25419
M67764
N72126
S25500

R32990
S25208
S25421
M67765
N72152
S25501

R32994
S25221
S25422
M67784
N72162
S25502

R33000
S25229
S25430
M67791
N72207
S25505

R33004
S25238
S25437
M67792
N72216
S25506

R33040
S25246
S25439
M67793
N72219
S25507

R33055
S25248
S25449
M67794
N72242
S25508

R33059
S25250
R33186
M67795
P66693
S25509

R33077
S25256
S25528
M67796
P66695
S25514

R33080
S25262

M67797
P66696
S25529

R33082
S25268

M67798
P66698
S25532

R33086
S25278

M67799
P66699
S25541

R33087
S25287

M67800
P66737
S25543

R33089
S25288

M67801
P66753
S25544

R33090

(ii) Thereafter, reinspect at intervals that correspond to the selected inspection interval.
(3) If a fan hub is identified in both Table 2 of this AD and Appendix A of PW ASB No. A6272, dated September 24, 1996, inspect in accordance with paragraph (a)(1) or (a)(2) of this AD, whichever occurs first.
(4) For fan hubs with S/Ns not listed in Table 2 of this AD or in Appendix A of PW ASB No. A6272, dated September 24, 1996, after the fan hub has accumulated more than 4,000 CSN, inspect the next time the fan hub is in the shop at piece-part level, but not to exceed 10,000 CIS after March 5, 1997.
(5) Prior to further flight, remove from service fan hubs found cracked or that exceed the bushed hole acceptance criteria described in PW ASB No. A6272, dated September 24, 1996.
(b) Report the number of completed inspections on a monthly basis and report findings of cracked fan hubs in accordance with Accomplishment Instructions, Paragraph F, of Attachment 1 to PW ASB No. A6272, dated September 24, 1996, within 48 hours after inspection to Robert Guyotte, Manager, Engine Certification Branch, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (617) 238-7142, fax (617) 238-7199; Internet: Robert.Guyotte@faa.dot.gov. Reporting requirements have been approved by the Office of Management and Budget and assigned OMB control number 2120-0056.
(c) 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 forward their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office. Alternative methods of compliance approved for AD 97-02-11 are also considered approved for this AD.
Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Engine Certification Office.
(d) 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 requirements of this AD can be accomplished.
(e) The actions required by this AD shall be done in accordance with the following PW ASB:

Document No.
Pages
Date
A6272
1-21 Original
September 24, 1996
NDIP-892
1-30 A
September 15, 1996
Attachment I
AI-1-
AI-4 A
September 15, 1996
Total Pages: 55.

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.
(f) This amendment becomes effective on September 30, 1997.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 97-02-11, Amendment 39-9896 (62 FR 4902, February 3, 1997), applicable to Pratt & Whitney (PW) JT8D-200 series turbofan engines, was published in the Federal Register on February 24, 1997 (62 FR 8198), and a correction to a printing error in a table was published on March 31, 1997 (62 FR 15225). That action proposed to require cleaning, initial and repetitive eddy current inspections (ECI) and fluorescent penetrant inspections (FPI) for cracks of tierod and counterweight holes; removal of bushings; the cleaning and initial and repetitive ECI and FPI of bushed holes for cracks; and, if necessary, replacing with serviceable parts.
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.
Three commenters state that the March 5, 1997, date to begin counting cycles is objectionable, as a retroactive date is unenforceable. The FAA concurs in part. The March 5, 1997, date is supported by a safety risk analysis, but basing the cyclic count on this date would require immediate removal of parts not in compliance at the effective date of this AD. However, the FAA has reviewed a new risk analysis that uses the effective date of this AD to begin the cyclic count for fan hubs added to Table 2 of this AD. This final rule has been revised by changing the compliance time to "315 cycles from the effective date of this AD". This new date should prevent any fan hubs from being out of compliance at the date of final rule publication. It does not, however, extend the compliance time for those fan hubs that were previously included in AD 97-02-11 and are now listed in Table 2 of this AD. Fan hubs previously included in AD 97-02-11 must perform initial inspections to the more conservative compliance times.
One group of commenters object to the monthly reporting requirements required in the proposed rule, as these requirements are burdensome and do not contribute to safety. The FAA does not concur. The reports received from these inspections are used to validate the assumptions used in the safety risk analysis and are critical to the safety assessment of the inspection program.
One commenter states that alternative methods of compliance (AMOCs) approved in the current AD should be included in this superseded AD. The FAA concurs and has added a statement to this final rule that approves AMOCs from AD 97-02-11 as acceptable for this AD.
After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes described previously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.
There are approximately 2,624 enginesof the affected design in the worldwide fleet. The FAA estimates that 1,279 engines installed on aircraft of U.S. registry will be affected by this AD, that it will take 20 work hours per engine for 360 engines to disassemble, remove, inspect, and reassemble engines, and 4 work hours per engine for 919 engines to inspect at piece-part exposure, and that the average labor rate is $60 per work hour. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $862,560.
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.
For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it 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 removing amendment 39-9896 (62 FR 4902, February 3, 1997) and by adding a new airworthiness directive to read as follows: