AD 98-12-32

This amendment adopts a new airworthiness directive (AD), applicable to CFM International (CFMI) CFM56-2, -2A, -2B, -3, -3B, and -3C series turbofan engines, that requires a one-time eddy current inspection (ECI) for cracks or gouges in certain high pressure turbine rotor (HPTR) disks. This amendment is prompted by a report of a HPTR disk found to have a crack in a rim bolt hole during a routine shop manual ECI. The actions specified by this AD are intended to prevent the potential for an uncontained failure of the HPTR disk, which could result in an inflight engine shutdown, aborted takeoff, or damage to the aircraft.

Final rule.

98-12-32 CFM International: Amendment 39-10585. Docket 97-ANE-46-AD.
Applicability: CFM International (CFMI) CFM56-2, -2A, -2B, -3, -3B, and -3C series turbofan engines installed on, but not limited to McDonnell Douglas DC-8 series, Boeing 737 series, as well as Boeing E-3, E-6, and KC-135 (military) 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 notbeen eliminated, the request should include specific proposed actions to address it.
Compliance: Required as indicated, unless accomplished previously.
To prevent the potential for an uncontained failure of the high pressure turbine rotor (HPTR) disk, which could result in an inflight engine shutdown, aborted takeoff, or damage to the aircraft, accomplish the following:
(a) Eddy current inspect for cracks or gouges in HPTR disks, Part Numbers 1475M29P01, 1475M29P02, 9514M69P01, 9514M69P04, 9514M69P05, 9514M69P06, and 9514M69P09, with Serial Numbers listed in Table 1 of the applicable Service Bulletin (SB), as follows:
(1) For CFM56-2 engines, in accordance with CFM56-2 SB No. 72-817, Revision 1, dated November 25, 1997, within 45 days after the effective date of this AD.
(2) For CFM56-2A engines, in accordance with CFM56-2A SB No. 72-419, Revision 2, dated November 14, 1997, within 500 cycles in service (CIS) after the effective date of this AD, or by December 31, 1999, whichever occurs first.
(3) For CFM56-2B engines, in accordance with CFM56-2B SB No. 72-561, Revision 1, dated January 31, 1997, within 500 CIS after the effective date of this AD, or by December 31, 1999, whichever occurs first.
(4) For CFM56-3, -3B, and -3C engines, in accordance with CFM56-3/-3B/-3C SB No. 72-843, Revision 1, dated November 25, 1997, within 45 days after the effective date of this AD.
(b) Remove from service HPTR disks found cracked or gouged, and replace with serviceable parts.
(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 submit their request 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.
(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 inspection requirements of this AD can be accomplished.
(e) The actions required by this AD shall be done in accordance with the following CFMI SBs:

Document No
Pages
Revision
Date
CFM56-2 SB No. 72-817
1-2
1
November 25, 1997

3-12
Original
January 14, 1997

13
1
November 25, 1997

14-19
Original
January 14, 1997
Total Pages: 19.

CFM56-2A SB No. 72-419
1-2
2
November 14, 1997

3-4
1
January 31, 1997

5-10
Original
January 14, 1997

11-12
2
November 14, 1997

13-18
Original
January 14, 1997
Total Pages: 18.

CFM56-2B SB No. 72-561
1
1
January 31, 1997

2
Original
January 14, 1997

3-4
1
January 31, 1997

5-19
Original
January 14, 1997
Total Pages: 19.

CFM56-3/-3B/-3C SB No. 72-843
1-2
1
November 25, 1997

3-11
Original
January 14, 1997

12
1
November 25, 1997

13-18
Original
January 14, 1997
Total Pages: 18.

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, 1 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 Regional 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 July 20, 1998.

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, and -3C series turbofan engines was published in the Federal Register on January 22, 1998 (63 FR 3275). That action proposed to require a one-time eddy current inspection for cracks or gouges in certain high pressure turbine rotor (HPTR) disks in accordance with CFM56-2 Service Bulletin (SB) No. 72-817, dated January 14, 1997, CFM56-2A SB No. 72-419, Revision 1, dated January 31, 1997, CFM56-2B SB No. 72-561, Revision 1, dated January 31, 1997, and CFM56-3/-3B/-3C SB No. 72-843, dated January 14, 1997.
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 support the rule as proposed.
Since issuance of the proposed rule, CFMI has revised CFM56-2 SB No. 72-817, CFM56-2A SB No. 72-419, and CFM56-3/-3B/-3C SB No. 72-843. These revisions include an update of a HPTR disk serial number identified in Table 1. Therefore, since these SB revisions do not alter the proposed actions, this AD will include reference to CFM56-2 SB No. 72-817, Revision 1, dated November 25, 1997, CFM56-2A SB No. 72-419, Revision 2, dated November 14, 1997, and CFM56-3/-3B/-3C SB No. 72-843, Revision 1, dated November 25, 1997, for the accomplishment of the HPTR disk inspections.
In addition, this AD revises the compliance date requirement for CFM56-2, CFM56-3, -3B, and -3C engines to 45 days after the effective date of 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 as proposed.
There are approximately 276 engines of the affected design in the worldwide fleet. The FAA estimates that 100 engines installed on aircraft of U.S. registry will be affected by this AD, that it will take approximately 300 work hours per engine to accomplish the required actions, and that the average labor rate is $60 per work hour. Replacement parts, if required, would cost approximately $86,000 per engine. Based on these figures, and assuming that 16 of the inspected HPTR disks will require replacement, the total cost impact of the AD on U.S. operators is estimated to be $3,176,000. The manufacturer has advised the FAA that certain costs incurred from the inspection and replacement of parts affected by this AD may be borne by the manufacturer; therefore, the total cost impact of this AD to U.S. operators may be less than estimated by the FAA.
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 adding the following new airworthiness directive: