[Federal Register Volume 74, Number 89 (Monday, May 11, 2009)]
[Proposed Rules]
[Pages 21772-21774]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-10956]


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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]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for CFM International, S.A. CFM56-7B series turbofan engines. This 
proposed AD would require initial and repetitive eddy current 
inspections (ECIs) of certain part number (P/N) low-pressure (LP) 
turbine rear frames. This proposed 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 proposing 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: We must receive any comments on this proposed AD by July 10, 
2009.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD.
     Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 1200 New Jersey Avenue, SE., West Building Ground 
Floor, Room W12-140, Washington, DC 20590-0001.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
     Fax: (202) 493-2251.

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]; (781) 238-7199.
    Contact CFM International, Technical Publications Department, 1 
Neumann Way, Cincinnati, OH 45215; telephone (513) 552-2800; fax (513) 
552-2816, for a copy of the service information identified in this 
proposed AD.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send us any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2009-0236; Directorate 
Identifier 2009-NE-06-AD'' in the subject line of your comments. We 
specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of the proposed AD. We will consider 
all comments received by the closing date and may amend the proposed AD 
in light of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We

[[Page 21773]]

will also post a report summarizing each substantive verbal contact 
with FAA personnel concerning this proposed AD. Using the search 
function of the Web site, anyone can find and read the comments in any 
of our dockets, including, if provided, the name of the individual who 
sent the comment (or signed the comment on behalf of an association, 
business, labor union, etc.). You may review the DOT's complete Privacy 
Act Statement in the Federal Register published on April 11, 2000 (65 
FR 19477-78).

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 proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Operations office (telephone (800) 647-5527) is 
the same as the Mail address provided in the ADDRESSES section. 
Comments will be available in the AD docket shortly after receipt.

Discussion

    CFM International, S.A. performed a refined life analysis that 
identified the need for initial and repetitive inspection thresholds 
for LP turbine rear frames, P/Ns 340-166-254-0; 340-166-255-0; 340-166-
256-0; 340-166-257-0; 340-166-258-0; 340-166-259-0; P/N 340-177-551-0; 
340-177-552-0; 340-177-553-0; 340-177-554-0; 340-177-555-0; and 340-
177-556-0. These LP turbine rear frames are installed on CFM56-7B 
series turbofan engines. This proposed AD would require initial and 
repetitive ECIs of these LP turbine rear frames. This condition, if not 
corrected, could result in engine separation from the airplane, 
possibly leading to loss of control of the airplane.

Relevant Service Information

    We have reviewed and approved the technical contents of CFM 
International, S.A. Service Bulletin (SB) No. CFM56-7B S/B 72-0558, 
Revision 2, dated December 1, 2008, and SB No. CFM56-7B S/B 72-0579, 
Revision 4, dated December 1, 2008, that describe procedures for 
performing initial and repetitive ECIs of the LP turbine rear frame.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other products 
of this same type design. We are proposing this AD, which would require 
initial and repetitive ECIs of the affected P/N LP turbine rear frames. 
The proposed AD would require you to use the service information 
described previously to perform these actions.

Costs of Compliance

    We estimate that this proposed AD would affect 1,228 CFM56-7B 
series turbofan engines installed on airplanes of U.S. registry. We 
estimate that it would 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 replacement LP turbine rear frame costs about 
$275,000. If all 1,228 LP turbine rear frames needed replacement, we 
estimate the total cost of the proposed AD to U.S. operators to be 
$33,994,720.

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 proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 the proposed AD:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866;
    2. Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979); and
    3. Would 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 regulatory evaluation of the estimated costs to 
comply with this proposed AD. 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.

The Proposed Amendment

    Under the authority delegated to me by the Administrator, the 
Federal Aviation Administration proposes to amend 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. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive:

CFM International, S.A: Docket No. FAA-2009-0236; Directorate 
Identifier 2009-NE-06-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by July 10, 
2009.

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; -7B26/B2; -7B20/3; -
7B22/3; -7B24/3; -7B26/3; -7B27/3; -7B22/3B1; -7B24/3B1; -7B27/3B1; 
-7B26/3B1; -7B26/3B2; -7B26/3F; -7B27/3; -7B27/3F; -7B26/3B2F; -
7B27/3B1F; -7B27/3B3; and -7B27A turbofan engines assembled with a 
low-pressure (LP) turbine rear frame, part number (P/N) 340-166-254-
0; 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

[[Page 21774]]

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; -7B26/B2; -7B20/3; -7B22/3; -
7B24/3; -7B26/3; -7B27/3; -7B22/3B1; -7B24/3B1; -7B27/3B1; -7B26/
3B2; -7B26/3F; -7B27/3F; -7B26/3B2F; -7B27/3B1F; and -7B27A turbofan 
engines with an LP turbine rear frame, P/N 340-166-254-0; 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 4, dated December 1, 2008.
    (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 4, dated December 1, 2008, 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; -7B27/3; -7B26/
3B1; and -7B27/3B3 turbofan engines with an LP turbine rear frame, 
P/N 340-166-254-0; 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 4, dated December 1, 2008.
    (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 4, dated December 1, 2008, 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 2, dated December 1, 2008.
    (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 2, dated December 1, 2008, 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.

Alternative Methods of Compliance

    (i) 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

    (j) European Aviation Safety Agency AD 2009-0009, dated January 
15, 2009, also addresses the subject of this AD.
    (k) Contact CFM International, Technical Publications 
Department, 1 Neumann Way, Cincinnati, OH 45215; telephone (513) 
552-2800; fax (513) 552-2816, for a copy of the service information 
identified in this AD.
    (l) 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]; 238-7751; fax (781) 238-7199, for more 
information about this AD.

    Issued in Burlington, Massachusetts, on May 4, 2009.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E9-10956 Filed 5-8-09; 8:45 am]
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