[Federal Register Volume 73, Number 89 (Wednesday, May 7, 2008)]
[Proposed Rules]
[Pages 25597-25599]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-10050]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0174; Directorate Identifier 2008-NE-03-AD]
RIN 2120-AA64


Airworthiness Directives; CFM International, S.A. CFM56-5B1/P; -
5B2/P; -5B3/P; -5B3/P1; -5B4/P; -5B4/P1; -5B5/P; -5B6/P; -5B7/P; -5B8/
P; and -5B9/P Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (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. CFM56-5B1/P; -5B2/P; -5B3/P; -5B3/P1; -5B4/
P; -5B4/P1; -5B5/P; -5B6/P; -5B7/P; -5B8/P; and -5B9/P 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 
lifing analysis by the engine manufacturer that shows the need to 
identify initial and repetitive inspection thresholds for inspecting 
certain LP turbine rear frames. We are proposing this AD to detect low-
cycle-fatigue cracks in the LP turbine rear frame, which 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 7, 
2008.

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.
    You can get the service information identified in this proposed AD 
from CFM International, Technical Publications Department, 1 Neumann 
Way, Cincinnati, OH 45215; telephone (513) 552-2800; fax (513) 552-
2816.

FOR FURTHER INFORMATION CONTACT: Stephen Sheely, Aerospace Engineer,

[[Page 25598]]

Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; e-mail: 
[email protected]; telephone (781) 238-7750; fax (781) 238-7199.

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-2008-0174; Directorate 
Identifier 2008-NE-03-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 
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 lifing analysis that 
shows the need to identify initial and repetitive inspection thresholds 
for inspecting LP turbine rear frames, P/Ns 338-171-703-0; 338-171-704-
0; 338-171-705-0; and 338-171-706-0. These parts are installed in 
CFM56-5B1/P; -5B2/P; -5B3/P; -5B3/P1; -5B4/P; -5B4/P1; -5B5/P; -5B6/P; 
-5B7/P; -5B8/P; and -5B9/P 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 low-cycle-fatigue 
cracks in the LP turbine rear frame, 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 No. CFM56-5B S/B 72-0620, Revision 
1, dated December 20, 2007, that describes procedures for performing 
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.

Costs of Compliance

    We estimate that this proposed AD would affect 426 CFM56-5B 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 
$102,240. If all 426 LP turbine rear frames needed replacement, we 
estimate the total cost of the proposed AD to U.S. operators to be 
$43,656,480.

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, 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-2008-0174; Directorate 
Identifier 2008-NE-03-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by July 7, 
2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to CFM International, S.A. CFM56-5B1/P; -
5B2/P; -5B3/P; -5B3/P1; -5B4/P; -5B4/P1; -5B5/P; -5B6/P; -5B7/P; -
5B8/P; and -5B9/P turbofan engines with

[[Page 25599]]

low-pressure (LP) turbine rear frames, part numbers 338-171-703-0; 
338-171-704-0; 338-171-705-0; and 338-171-706-0, installed. These 
engines are installed on, but not limited to, Airbus A318, A319, 
A320, and A321 series airplanes.

Unsafe Condition

    (d) This AD results from a refined lifing analysis by the engine 
manufacturer that shows the need to identify initial and repetitive 
inspection thresholds for inspecting certain LP turbine rear frames. 
We are issuing this AD to detect low-cycle-fatigue cracks in the LP 
turbine rear frame, which 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.

Initial Inspection

    (f) Perform an initial eddy current inspection (ECI) of the LP 
turbine rear frame using paragraphs 3.A. through 3.A.(7)(d) of the 
Accomplishment Instructions of CFM International, S.A. Service 
Bulletin (SB) No. CFM56-5B S/B 72-0620, Revision 1, dated December 
20, 2007, at the following compliance times:
    (1) For commercial engine applications, within 25,000 cycles-
since-new (CSN) on the LP turbine rear frame.
    (2) For corporate engine applications, within 19,000 CSN on the 
LP turbine rear frame.
    (3) For engines with unknown LP turbine rear frame CSN, within 
300 cycles from the effective date of this AD.

Repetitive Inspections

    (g) Perform repetitive ECIs of the LP turbine rear frame using 
paragraphs 3.A. through 3.A.(7)(d) of the Accomplishment 
Instructions of CFM International, S.A. SB No. CFM56-5B S/B 72-0620, 
Revision 1, dated December 20, 2007. Use the inspection intervals in 
paragraph 3.A.(8) of the Accomplishment Instructions of CFM 
International, S.A. SB No. CFM56-5B S/B 72-0620, Revision 1, dated 
December 20, 2007.

LP Turbine Rear Frame Removal Criteria

    (h) Remove LP turbine rear frames from service that have a 
single crack length of 2.56 inches (65 mm) or longer, or multiple 
cracks with accumulated crack length of 2.56 inches (65 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 2007-0221, dated August 
13, 2007, also addresses the subject of this AD.
    (k) Contact Stephen Sheely, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
[email protected]; telephone (781) 238-7750; fax (781) 238-
7199, for more information about this AD.

    Issued in Burlington, Massachusetts, on April 29, 2008.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
 [FR Doc. E8-10050 Filed 5-6-08; 8:45 am]
BILLING CODE 4910-13-P