AD 96-18-16 ACTIVE

This amendment adopts a new airworthiness directive (AD), applicable to CFM International (CFMI) CFM56-2/-2A/-2B/-3/-3B/-3C/-5 series turbofan engines, that requires part number reidentification of certain low pressure turbine rotor (LPTR) stub shafts and conical supports, and reduction of the low cycle fatigue (LCF) retirement lives for these reidentified parts. This amendment is prompted by the results of a refined life analysis performed by the manufacturer which revealed minimum calculated LCF lives significantly lower than published LCF retirement lives. The actions specified by this AD are intended to prevent an LCF failure of the LPTR stub shaft and conical support, which could result in an uncontained engine failure and damage to the aircraft.

Final rule.

96-18-16 CFM International: Amendment 39-9742. Docket 95-ANE-15.
Applicability: CFM International (CFMI) CFM56-2/-2A/-2B/-3/-3B/-3C/-5 series turbofan engines installed on, but not limited to Airbus A319 and A320 series, McDonnell Douglas DC-8 series, and Boeing 737, as well as Boeing E-3, E-6, and KC-135 (military) series aircraft.
Note: 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 (k) 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 a low cycle fatigue (LCF) failure of the low pressure turbine rotor (LPTR) stub shaft and conical support, which could result in an uncontained engine failure and damage to the aircraft, accomplish the following:
(a) Reidentify CFM56-2A LPTR stub shafts, Part Numbers (P/N) 301-330-623-0 and 301-330-624-0, with Serial Numbers (S/N) listed in Table 2 of CFMI CFM56-2A Service Bulletin (SB) No. 72-338, dated November 25, 1993, in accordance with the Accomplishment Instructions of CFMI CFM56-2A SB No. 72-338, dated November 25, 1993, at the next piece-part exposure after the effective date of this AD, but not to exceed 6,400 cycles since new (CSN).
(b) Reidentify CFM56-2B LPTR stub shafts, P/N 301-330-618-0, 301-330-619-0, 301-330- 623-0, and 301-330-624-0, with S/N listed in Table 2 of CFMI CFM56-2B SBNo. 72-476, dated December 7, 1993, in accordance with the Accomplishment Instructions of CFMI CFM56-2B SB No. 72-476, dated December 7, 1993, at the next piece-part exposure after the effective date of this AD, but not to exceed 8,300 CSN.
(c) Reidentify CFM56-2 LPTR conical supports, P/N 305-056-106-0, 305-056-109-0, 305- 056-110-0, and 305-056-111-0, with S/N listed in Table 1 of CFMI CFM56-2 SB No. 72-728, Revision 2, dated December 21, 1994, in accordance with the Accomplishment Instructions of CFMI CFM56-2 SB No. 72-728, Revision 2, dated December 21, 1994, at the next piece-part exposure after the effective date of this AD, but not to exceed 18,000 CSN.
(d) Reidentify CFM56-2A LPTR conical supports, P/N 305-056-110-0 and 305-056-111-0, with S/N listed in Table 1 of CFMI CFM56-2A SB No. 72-338, dated November 25, 1993, in accordance with the Accomplishment Instructions of CFMI CFM56-2A SB No. 72-338, dated November 25, 1993, at the next piece-part exposure after the effective date of this AD, but not to exceed 5,700 CSN.
(e) Reidentify CFM56-2B LPTR conical supports, P/N 305-056-106-0, 305-056-109-0, 305- 056-110-0, and 305-056-111-0, with S/N listed in Table 1 of CFMI CFM56-2B SB No. 72-476, dated December 7, 1993, in accordance with the Accomplishment Instructions of CFMI CFM56-2B SB No. 72-476, dated December 7, 1993, at the next piece-part exposure after the effective date of this AD, but not to exceed 8,700 CSN.
(f) Reidentify CFM56-3/-3B/-3C LPTR stub shafts, P/N 301-330-618-0, 301-330-619-0, 301-330-623-0, and 301-330-624-0, with S/N listed in Table 2 of CFMI CFM56-3/-3B/-3C SB No. 72-695, dated November 25, 1993, in accordance with the Accomplishment Instructions of CFMI CFM56-3/-3B/-3C SB No. 72-695, dated November 25, 1993, as follows:
(1) For CFM56-3/-3B/-3C series engines operating at the Category A thrust rating, at the next piece-part exposure after the effective date of this AD, but not to exceed a total Category A thrust ratinglife of 20,000 CSN.
(2) For CFM56-3B/-3C series engines operating at the Category B thrust rating, at the next piece-part exposure after the effective date of this AD, but not to exceed a total Category B thrust rating life of 11,400 CSN.
(3) For CFM56-3C series engines operating at the Category C thrust rating, at the next piece-part exposure after the effective date of this AD, but not to exceed a total Category C thrust rating life of 7,900 CSN.
(g) Reidentify CFM56-3/-3B/-3C LPTR conical supports, P/N 305-056-106-0, 305-056-109- 0, 305-056-110-0, and 305-056-111-0, with S/N listed in Table 1 of CFMI CFM56-3/-3B/-3C SB No. 72-695, dated November 25, 1993, in accordance with the Accomplishment Instructions of CFMI CFM56-3/-3B/-3C SB No. 72-695, dated November 25, 1993, as follows:
(1) For CFM56-3/-3B/-3C series engines operating at the Category A thrust rating, at the next piece-part exposure after the effective date of this AD, but not to exceed a total Category A thrust rating life of 12,100 CSN.
(2) For CFM56-3B/-3C series engines operating at the Category B thrust rating, at the next piece-part exposure after the effective date of this AD, but not to exceed a total Category B thrust rating life of 9,300 CSN.
(3) For CFM56-3C series engines operating at the Category C thrust rating, at the next piece-part exposure after the effective date of this AD, but not to exceed a total Category C thrust rating life of 5,700 CSN.
(h) Remove from service CFM56-5 LPTR conical support, P/N 336-000-305-0, prior to accumulating 11,300 CSN.
(i) This action establishes new LCF retirement lives for parts reidentified in accordance with paragraphs (a) through (g) of this AD, and the new LCF retirement life noted in paragraph (h) of this AD, which are published in Chapter 05 of the applicable engine shop manual (CFM56-2 CFMI-TP.SM.4, CFM56-2A/-2B CFMI-TP.SM.6, CFM56-3 CFMI-TP.SM.5, and CFM56-5 CFMI-TP.SM.7).
(j) The Category A, B, and C thrust ratingnoted in paragraphs (f) and (g) of this AD are defined in Chapter 05 of CFM56-3 engine shop manual, CFMI-TP.SM.5.
(k) 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. The request should be forwarded through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office.
Note: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine Certification Office.
(l) 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.
(m) The actions required by this AD shall be done in accordance with the following CFMI SB's:

Document No.
Pages
Revision
Date

CFM56-2 SB No. 72-728
1
2
December 21, 1994

2-7
Original
November 25, 1993

8
2
December 21, 1994

9
Original
November 25, 1993

Total Pages: 9.

CFM56-2A SB No. 72-338
1-8
Original
November 25, 1993
Total Pages: 8.

CFM56-2B SB No. 72-476
1-9
Original
December 7, 1993
Total Pages: 9.

CFM56-3/-3B/-3C

SB No. 72-695
1-9
Original
November 25, 1993
Total Pages: 9.

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 CFM International, Technical Publications Department, One Neumann Way, Cincinnati, OH 45215; telephone (513) 552-2981, fax (513) 552-2816. 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.
(n) This amendment becomes effective on December 9, 1996.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to CFM International (CFMI) CFM56-2/-2A/-2B/-3/-3B/-3C/-5 series turbofan engines was published in the Federal Register on September 1, 1995 (60 FR 45683). That action proposed to require part number reidentification of certain low pressure turbine rotor (LPTR) stub shafts and conical supports, and reduction of the low cycle fatigue (LCF) retirement lives for these reidentified parts in accordance with the following CFMI service bulletins (SB's): CFM56-2 SB No. 72-728, Revision 2, dated December 21, 1994, CFM56-2A SB No. 72-338, dated November 25, 1993, CFM56-2B SB No. 72- 476, dated December 7, 1993, and CFM56-3/-3B/-3C SB No. 72-695, dated November 25, 1993.
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.
Two commenters support the rule as proposed.
One commenter states that CFM56-3 series engines should be included in compliance paragraph (f) of the proposed rule. The FAA concurs, and paragraph (f) of this final rule has been revised accordingly.
One commenter suggests that the proposed rule be revised to address the LCF retirement lives of CFM56-3B and CFM56-3C series engines that are operated at reduced thrust ratings, since the lives are dependent on the thrust rating. The FAA concurs. Paragraphs (f) and (g) of this final rule have been revised, and paragraph (j) has been added accordingly.
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.
The FAA estimates that 41engines installed on aircraft of U.S. registry will be affected by this AD, that it will take approximately 0.25 work hours per engine to accomplish the required actions, and that the average labor rate is $60 per work hour. Assuming that the parts cost is proportional to the reduction of the LCF retirement lives, the required parts will cost approximately $6,687 per engine. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $274,782.
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) isnot 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 USC 106(g), 40113, 44701. 39.13 - [AMENDED]
2. Section 39.13 is amended by adding the following new airworthiness directive:

The service information referenced in this AD may be obtained from CFM
International, Technical Publications Department, One Neumann Way, Cincinnati, OH 45215;
telephone (513) 552-2981, fax (513) 552-2816. This information may be examined at the Federal
Aviation Administration (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.

Glorianne Messemer, Aerospace Engineer, Engine
Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park,
Burlington, MA 01803-5299; telephone (617) 238-7132; fax (617) 238-7199.