Document ID: FAA-2009-0606-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; CFM International, S.A Model CFM56-3B1 and -3B2 Turbofan Engines
Posted Date: 2009-07-23T04:00Z

[Federal Register: July 23, 2009 (Volume 74, Number 140)]
[Proposed Rules]               
[Page 36420-36422]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr23jy09-8]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0606; Directorate Identifier 2009-NE-11-AD]
RIN 2120-AA64

 
Airworthiness Directives; CFM International, S.A Model CFM56-3B1 
and -3B2 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 certain CFM International Model CFM56-3B1 and -3B2 turbofan 
engines. This proposed AD would require initial and repetitive 
inspections for damage to the fan blades. This proposed AD results from 
a report of a failed fan blade with severe out-of-limit wear on the 
underside of the blade platform where it contacts the damper. We are 
proposing this AD to prevent failure of multiple fan blades, which 
could result in an uncontained failure of the engine and damage to the 
airplane.

DATES: We must receive any comments on this proposed AD by September 
21, 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.
    Contact CFM International, S. A., Technical Publication 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.

[[Page 36421]]

FOR FURTHER INFORMATION CONTACT: Stephen K. Sheely, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; e-mail: 
stephen.k.sheely@faa.gov; 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-2009-0606; Directorate 
Identifier 2009-NE-11-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

    On February 13, 2006, we received a report of a failed fan blade 
with a 25 degrees midspan shroud. The underside of the blade platform 
had severe out-of-limit wear at a contact point with the damper. We 
couldn't determine the exact root cause for the wear. However, poor 
damping of the 25 degrees midspan shroud blade set due to severe wear 
on several dampers and the undersides of the fan blade platforms 
contributed to high dynamic stress levels seen on this set of blades. 
This condition, if not corrected, could result in failure of multiple 
fan blades, which could result in an uncontained failure of the engine 
and damage to the airplane.

Relevant Service Information

    We have reviewed and approved the technical contents of CFM 
International Service Bulletin (SB) CFM56-3/3B/3C S/B 72-1067, dated 
February 15, 2007, that describes procedures for performing on-wing and 
in-shop inspections for wear.

Differences Between the Proposed AD and the Manufacturer's Service 
Information

    CFM International SB CFM56-3/3B/3C S/B 72-1067, dated February 15, 
2007, requires an initial inspection within 6 months. This proposed AD 
would require the initial inspection within 3,000 cycles-in-service 
(CIS) after the effective date of the proposed AD. CFM International SB 
CFM56-3/3B/3C S/B 72-1067, dated February 15, 2007, also requires a 
repetitive inspection within 1,500 to 3,000 cycles-since-last 
inspection (CSLI). This proposed AD would require the repetitive 
inspection within 3,000 CSLI.

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 
performing initial and repetitive inspections of the fan blade for 
wear. 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 50 engines installed 
on airplanes of U.S. registry. We also estimate that it would take 
about 8 work-hours per engine to perform the proposed actions, and that 
the average labor rate is $80 per work-hour. Required parts would cost 
about $38,000 per engine. Based on these figures, we estimate the total 
cost of the proposed AD to U.S. operators to be $1,932,000.

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:

[[Page 36422]]

    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-2009-0606; Directorate 
Identifier 2009-NE-11-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by September 
21, 2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to CFM International S.A. model CFM56-3B1 
and -3B2 turbofan engines with 25 degrees midspan shroud fan blades, 
part numbers (P/Ns) 9527M99P08, 9527M99P09, 9527M99P10, 9527M99P11, 
1285M39P01, or fan blade pairs, P/Ns 335-088-901-0, 335-088-902-0, 
335-088-903-0, and 335-088-904-0 installed. These engines are 
installed on, but not limited to, Boeing 737 series airplanes.

Unsafe Condition

    (d) This AD results from a report of a failed fan blade with 
severe out-of-limit wear on the underside of the blade platform 
where it contacts the damper. We are issuing this AD to prevent 
failure of multiple fan blades, which could result in an uncontained 
failure of the engine and damage to 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.

Inspection for Wear

    (f) Within 3,000 cycles-in-service after the effective date of 
this AD, perform an on-wing or in-shop inspection of the fan blade 
and damper for wear. Use paragraph 3. Accomplishment Instructions of 
CFM International Service Bulletin (SB) CFM56-3/3B/3C S/B 72-1067, 
dated February 15, 2007.
    (g) If you find wear, perform additional inspections as 
specified in paragraph 3. Accomplishment Instructions of CFM 
International SB CFM56-3/3B/3C S/B 72-1067, dated February 15, 2007.
    (h) Thereafter, within intervals not to exceed 3,000 cycles-
since-last inspection, perform an on-wing or in-shop inspection for 
wear. Use paragraph 3. Accomplishment Instructions of CFM 
International SB CFM56-3/3B/3C S/B 72-1067, dated February 15, 2007.
    (i) If you find wear, perform additional inspections as 
specified in paragraph 3. Accomplishment Instructions of CFM 
International SB CFM56-3/3B/3C S/B 72-1067, dated February 15, 2007.

Installation Prohibition

    (j) After the effective date of this AD, don't install any 25 
degrees midspan shroud fan blades, P/Ns 9527M99P08, 9527M99P09, 
9527M99P10, 9527M99P11, 1285M39P01, or fan blade pairs, P/Ns 335-
088-901-0, 335-088-902-0, 335-088-903-0, and 335-088-904-0, unless 
they have passed an inspection specified in paragraph 3. 
Accomplishment Instructions of CFM International SB CFM56-3/3B/3C S/
B 72-1067, dated February 15, 2007.

Optional Terminating Action

    (k) Replacing the 25 degrees midspan shroud fan blade set with a 
37 degrees midspan shroud fan blade set terminates the repetitive 
inspection requirements specified in paragraph (h) of this AD.

Alternative Methods of Compliance

    (l) 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

    (m) Contact Stephen K. Sheely, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
stephen.k.sheely@faa.gov; telephone (781) 238-7750; fax (781) 238-
7199, for more information about this AD.
    (n) CFM International SB CFM56-3/3B/3C S/B 72-1067, dated 
February 15, 2007, pertains to the subject of this AD. Contact CFM 
International, S. A., Technical Publication Department, 1 Neumann 
Way, Cincinnati, OH 45215; telephone (513) 552-2800; fax (513) 552-
2816, for a copy of this service information.
    (o) EASA airworthiness directive 2009-0036, dated February 20, 
2009, also addresses the subject of this AD.

    Issued in Burlington, Massachusetts, on July 16, 2009.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E9-17473 Filed 7-22-09; 8:45 am]

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