Airworthiness Directives; CFM International, S.A. CFM56-7B Series Turbofan Engines

[Federal Register Volume 75, Number 9 (Thursday, January 14, 2010)]
[Rules and Regulations]
[Pages 2064-2067]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-31043]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0236; Directorate Identifier 2009-NE-06-AD; 
Amendment 39-16162; AD 2010-01-05]
RIN 2120-AA64


Airworthiness Directives; CFM International, S.A. CFM56-7B Series 
Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for CFM 
International, S.A. CFM56-7B series turbofan engines. This AD requires 
initial and repetitive eddy current inspections (ECIs) of certain part 
number (P/N) low-pressure (LP) turbine rear frames. This AD results 
from a refined life analysis by the engine manufacturer that shows the 
need to identify an initial and repetitive inspection threshold for 
inspecting certain LP turbine rear frames. We are issuing this AD to 
prevent failure of the LP turbine rear frame from low-cycle-fatigue 
cracks. Failure of the LP turbine rear frame could result in engine 
separation from the airplane, possibly leading to loss of control of 
the airplane.

DATES: This AD becomes effective February 18, 2010. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in the regulations as of February 18, 2010.

ADDRESSES: You can get the service information identified in this AD 
from CFM International, Technical Publications Department, 1 Neumann 
Way, Cincinnati, OH 45215; telephone (513) 552-2800; fax (513) 552-
2816.
    The Docket Operations office is located at Docket Management 
Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, 
SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-
0001.

[[Page 2065]]


FOR FURTHER INFORMATION CONTACT: Antonio Cancelliere, Aerospace 
Engineer, Engine Certification Office, FAA, Engine and Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803; e-
mail: [email protected]; telephone (781) 238-7751; fax (781) 
238-7199.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 
with a proposed AD. The proposed AD applies to CFM International, S.A. 
CFM56-7B series turbofan engines. We published the proposed AD in the 
Federal Register on May 11, 2009 (74 FR 21772). That action proposed to 
require initial and repetitive ECIs of certain P/N LP turbine rear 
frames.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Operations office (telephone (800) 647-5527) is provided in 
the ADDRESSES section. Comments will be available in the AD docket 
shortly after receipt.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Request To Supersede or Revise Existing AD 2008-03-09

    One commenter, the Air Transport Association (ATA), requests that 
we should supersede or revise existing AD 2008-03-09 to incorporate the 
requirements and P/Ns affected by the proposed AD.
    We do not agree. Superseding or revising that AD to incorporate 
these requirements would make the requirements of existing AD 2008-03-
09 and this AD confusing. AD 2008-03-09 requires a change to the 
Airworthiness Limitations Section (ALS) for the introduction of the new 
LP turbine rear frame life limits, with inspections, while this AD 
introduces limits for LP turbine rear frame P/Ns that were introduced 
to the field before the ALS changes occurred. We did not change the AD.

Request To Reference the Latest Service Bulletins (SBs)

    ATA and CFM International, S.A. request that we reference the 
latest version of CFM International, S.A. SB No. CFM56-7B S/B 72-0579, 
which is Revision 5, dated March 30, 2009. CFM International also 
requests that we reference the latest version of CFM International, 
S.A. SB No. CFM56-7B S/B 72-0558, which is Revision 3, dated March 30, 
2009.
    We agree and changed the SB references in the AD.

Request To Include LP Turbine Rear Frame P/Ns

    ATA requests that we include turbine rear frame P/Ns 340-166-251-0; 
340-166-252-0; and 340-166-253-0. These P/Ns are included in the 
effectivity section of CFM International, S.A. SB No. CFM56-7B S/B 72-
0579, and Engine Manual 05-21-03. ATA also requests that we include LP 
turbine rear frame P/Ns 340-027-110-0 and 370-027-120-0. These P/Ns are 
included in the effectivity section of CFM International, S.A. SB No. 
CFM56-7B S/B 72-0568.
    We do not agree. This AD addresses LP turbine rear frame P/Ns 
introduced in the field by CFM International, S.A. through SB No. 
CFM56-7B S/B 72-0527, before the ALS could be modified to include the 
LP turbine rear frame P/Ns affected by this AD. The LP turbine rear 
frame P/Ns listed by ATA are already listed in the ALS. We did not 
change the AD.

Question Regarding Inclusion of LP Turbine Rear Frame P/Ns

    Japan Airlines (JAL) questions whether the LP turbine rear frame P/
Ns 340-166-251-0; 340-166-252-0; and 340-166-253-0 should be listed in 
this AD.
    The LP turbine rear frame P/Ns referred to by JAL are already 
listed in the ALS. We did not change the AD.

Request To Remove Engine Models

    ATA requests that we remove engine models CFM56-7B26/B2; CFM56-
7B26/3B2; and CFM56-7B26/3B2F from the proposed AD, as they are not 
affected.
    We agree and removed those models from the AD. We also advised CFM 
International, S.A., to remove those models from the effectivity list 
of SB No. CFM56-7B S/B 72-0579.

Request To Remove Repeated P/Ns

    ATA requests that we remove the repeated listings of LP turbine 
rear frame P/N 340-166-254-0 from the AD.
    We agree and removed the repeated P/N listings from the AD.

Request To Review and Correct an Engine Model

    ATA and CFM International, S.A. request that we review the engine 
model -7B27/3 in the proposed AD, as it appears to be incorrect. ATA 
states also that engine model -7B27/B3 is missing from the proposed AD.
    We agree. We corrected the -7B27/3 engine model in paragraph (g) to 
read ``-7B27/B3''. We also corrected the typographical error in 
paragraph (c)(1) so that engine model -7B27/3 is not duplicated. We 
changed the duplicate model to read ``-7B27/B3''.

Request To Remove an Engine Model

    ATA requests that we remove engine model -7B27A from paragraph (f) 
of the proposed AD, as it is not affected by the AD action.
    We agree and removed that engine model from the AD.

Previous Credit Paragraphs Added

    Since we issued the proposed AD, we became aware that we need to 
allow previous credit for initial inspections done before the effective 
date of the AD, using earlier versions of the applicable SBs. We added 
two previous credit paragraphs to the compliance section of the AD.

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting the AD with the changes described previously. 
We have determined that these changes will neither increase the 
economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    We estimate that this AD will affect 1,228 CFM56-7B series turbofan 
engines installed on airplanes of U.S. registry. We estimate that it 
will take about 3 work-hours to perform an eddy current inspection of 
an LP turbine rear frame. The average labor rate is $80 per work-hour. 
A new replacement LP turbine rear frame costs about $275,000. We 
estimate that all but the first of the recurrent inspections would 
occur during normally scheduled maintenance. Therefore, the cost of 
only the first inspection is included as directly attributable to this 
AD and we included that cost in the first year. Also, while we estimate 
that all 1,228 LP turbine rear frames will need replacement at some 
point in their 30-year useful life, only the unused cost of the part is 
attributable to this AD. Therefore, based on the service history of the 
LP turbine rear frame, we estimate the total cost of the AD to U.S. 
operators to be less than $11,266,490 annually based on a 30-year fleet 
life expectation.

[[Page 2066]]

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this AD will not have federalism 
implications under Executive Order 13132. This AD will not have a 
substantial direct effect 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.
    For the reasons discussed above, I certify that this AD:
    (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.
    We prepared a summary of the costs to comply with this AD and 
placed it in the AD Docket. You may get a copy of this summary at the 
address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the Federal Aviation Administration amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2010-01-05 CFM International, S.A: Amendment 39-16162. Docket No. 
FAA-2009-0236; Directorate Identifier 2009-NE-06-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective February 
18, 2010.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to:
    (1) CFM International, S.A. CFM56-7B20; -7B22; -7B24; -7B26; -
7B27; -7B22/B1; -7B24/B1; -7B27/B1; -7B26/B1; -7B20/3; -7B22/3; -
7B24/3; -7B26/3; -7B27/3; -7B22/3B1; -7B24/3B1; -7B27/3B1; -7B26/
3B1; -7B26/3F; -7B27/B3; -7B27/3F; -7B27/3B1F; and -7B27/3B3 
turbofan engines assembled with a low-pressure (LP) turbine rear 
frame, part number (P/N) 340-166-254-0; 340-166-255-0; 340-166-256-
0; 340-166-257-0; 340-166-258-0; or 340-166-259-0; and
    (2) CFM International, S.A. CFM56-7B20/2; -7B22/2; -7B24/2; -
7B26/2; and -7B27/2 turbofan engines assembled with a dual annular 
combustor and an LP turbine rear frame, P/N 340-177-551-0; 340-177-
552-0; 340-177-553-0; 340-177-554-0; 340-177-555-0; or 340-177-556-
0.
    (3) These engines are installed on, but not limited to, Boeing 
737-600, 737-700, 737-800, and 737-900 series airplanes.

Unsafe Condition

    (d) This AD results from a refined life analysis by the engine 
manufacturer that shows the need to identify an initial and 
repetitive inspection threshold for inspecting certain LP turbine 
rear frames. We are issuing this AD to prevent failure of the LP 
turbine rear frame from low-cycle-fatigue cracks. Failure of the LP 
turbine rear frame could result in engine separation from the 
airplane, possibly leading to loss of control of the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified unless the 
actions have already been done.

Inspections of LP Turbine Rear Frames

    (f) For CFM International, S.A. CFM56-7B20; -7B22; -7B24; -7B26; 
-7B27; -7B22/B1; -7B24/B1; -7B27/B1; -7B20/3; -7B22/3; -7B24/3; -
7B26/3; -7B27/3; -7B22/3B1; -7B24/3B1; -7B27/3B1; -7B26/3F; -7B27/
3F; and -7B27/3B1F turbofan engines with an LP turbine rear frame, 
P/N 340-166-254-0; 340-166-255-0; 340-166-256-0; 340-166-257-0; 340-
166-258-0; or 340-166-259-0, do the following:
    (1) Perform an initial eddy current inspection (ECI) of the LP 
turbine rear frame within 25,000 cycles-since-new (CSN) on the LP 
turbine rear frame.
    (2) For engines with unknown LP turbine rear frame CSN, perform 
an initial ECI within 300 cycles from the effective date of this AD.
    (3) Perform repetitive ECIs of the LP turbine rear frame, using 
the inspection intervals in paragraph 3.A. (8) of the Accomplishment 
Instructions of CFM International, S.A. SB No. CFM56-7B S/B 72-0579, 
Revision 5, dated March 30, 2009.
    (4) Use paragraphs 3.A. through 3.A. (7)(d) of the 
Accomplishment Instructions of CFM International, S.A. Service 
Bulletin (SB) No. CFM56-7B S/B 72-0579, Revision 5, dated March 30, 
2009, to do the ECIs.
    (5) Remove LP turbine rear frames from service that have a total 
cumulated crack length at any location, of 0.79 inch (20 mm) or 
longer.
    (g) For CFM International, S.A. CFM56-7B26/B1; -7B27/B3; -7B26/
3B1; and -7B27/3B3 turbofan engines with an LP turbine rear frame, 
P/N 340-166-254-0; 340-166-255-0; 340-166-256-0; 340-166-257-0; 340-
166-258-0; or 340-166-259-0, do the following:
    (1) Perform an initial ECI of the LP turbine rear frame within 
19,000 CSN on the LP turbine rear frame.
    (2) For engines with unknown LP turbine rear frame CSN, perform 
an initial ECI within 300 cycles from the effective date of this AD.
    (3) Perform repetitive ECIs of the LP turbine rear frame, using 
the inspection intervals in paragraph 3.A. (9) of the Accomplishment 
Instructions of CFM International, S.A. SB No. CFM56-7B S/B 72-0579, 
Revision 5, dated March 30, 2009.
    (4) Use paragraphs 3.A. through 3.A. (7)(d) of the 
Accomplishment Instructions of CFM International, S.A. Service 
Bulletin (SB) No. CFM56-7B S/B 72-0579, Revision 5, dated March 30, 
2009, to do the ECIs.
    (5) Remove LP turbine rear frames from service that have a total 
cumulated crack length at any location, of 0.79 inch (20 mm) or 
longer.
    (h) For CFM International, S.A. CFM56-7B20/2; -7B22/2; -7B24/2; 
-7B26/2; and -7B27/2 turbofan engines assembled with a dual annular 
combustor and an LP turbine rear frame, P/N 340-177-551-0; 340-177-
552-0; 340-177-553-0; 340-177-554-0; 340-177-555-0; or 340-177-556-
0, do the following:
    (1) Perform an initial ECI of the LP turbine rear frame within 
16,350 CSN on the LP turbine rear frame.
    (2) For engines with unknown LP turbine rear frame CSN, perform 
an initial ECI within 300 cycles from the effective date of this AD.
    (3) Perform repetitive ECIs of the LP turbine rear frame, using 
the inspection intervals in paragraph 3.A. (8) of the Accomplishment 
Instructions of CFM International, S.A. SB No. CFM56-7B S/B 72-0558, 
Revision 3, dated March 30, 2009.
    (4) Use paragraphs 3.A. through 3.A. (7)(d) of the 
Accomplishment Instructions of CFM International, S.A. SB No. CFM56-
7B S/B 72-0558, Revision 3, dated March 30, 2009, to do the ECIs.
    (5) Remove LP turbine rear frames from service that have a total 
cumulated crack length at any location, of 0.43 inch (11 mm) or 
longer.

[[Page 2067]]

Previous Credit

    (i) Initial inspection of LP turbine rear frames before the 
effective date of this AD performed using the Accomplishment 
Instructions of CFM International, S.A. SB No. CFM56-7B S/B 72-0579, 
original issue, Revision 1, Revision 2, Revision 3, or Revision 4, 
satisfy the requirements of paragraphs (f)(1), (f)(2), (g)(1), and 
(g)(2) of this AD.
    (j) Initial inspection of LP turbine rear frames before the 
effective date of this AD performed using the Accomplishment 
Instructions of CFM International, S.A. SB No. CFM56-7B S/B 72-0558, 
original issue, Revision 1, or Revision 2, satisfy the requirements 
of paragraphs (h)(1) and (h)(2) of this AD.

Alternative Methods of Compliance

    (k) The Manager, Engine Certification Office, has the authority 
to approve alternative methods of compliance for this AD if 
requested using the procedures found in 14 CFR 39.19.

Related Information

    (l) European Aviation Safety Agency AD 2009-0009 (corrected), 
dated January 27, 2009, also addresses the subject of this AD.
    (m) Contact Antonio Cancelliere, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
[email protected]; telephone (781) 238-7751; fax (781) 
238-7199, for more information about this AD.

Material Incorporated by Reference

    (n) You must use the service information specified in the 
following Table 1 to perform the inspections required by this AD. 
The Director of the Federal Register approved the incorporation by 
reference of the documents listed in the following Table 1 in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact CFM 
International, Technical Publications Department, 1 Neumann Way, 
Cincinnati, OH 45215; telephone (513) 552-2800; fax (513) 552-2816, 
for a copy of this service information. You may review copies at the 
FAA, New England Region, 12 New England Executive Park, Burlington, 
MA; or at the National Archives and Records Administration (NARA). 
For information on the availability of this material at NARA, call 
202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

                                       Table 1--Incorporation by Reference
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      Service Bulletin No.                     Page                  Revision                  Date
----------------------------------------------------------------------------------------------------------------
CFM56-7B S/B 72-0558...........  All............................               3  March 30, 2009.
    Total Pages: 22
CFM56-7B S/B 72-0579...........  All............................               5  March 30, 2009
    Total Pages: 23
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    Issued in Burlington, Massachusetts, on December 23, 2009.
Francis A. Favara,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. E9-31043 Filed 1-13-10; 8:45 am]
BILLING CODE 4910-13-P

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