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[Federal Register: April 1, 2010 (Volume 75, Number 62)]
[Proposed Rules]               
[Page 16361-16363]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr01ap10-21]                         

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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. Models CFM56-3 
and -3B Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of 
comment period.

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SUMMARY: This supplemental NPRM revises an earlier proposed 
airworthiness directive (AD), for certain CFM International, S.A. 
models CFM56-3 and -3B turbofan engines. That proposed AD would have 
required initial and repetitive inspections for damage to the fan 
blades. That proposed AD resulted 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. This supplemental NPRM revises the 
proposed AD to reduce the initial inspection compliance threshold, to 
correct the engine model designations affected, and to clarify some of 
the inspection wording in the compliance section. This supplemental 
NPRM 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 supplemental NPRM 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 supplemental NPRM by May 
17, 2010.

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, S. A., Technical Publication Department, 1 
Neumann Way, Cincinnati, OH 45215; telephone (513) 552-2800; fax (513) 
552-2816.

FOR FURTHER INFORMATION CONTACT: Antonio Cancelliere, Aerospace 
Engineer, Engine Certification Office, FAA, Engine & Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803; e-
mail: antonio.cancelliere@faa.gov; telephone (781) 238-7751; 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

[[Page 16362]]

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 July 16, 2009, we proposed to amend part 39 of the Code of 
Federal Regulations (14 CFR part 39) to add an AD for CFM 
International, S.A. models CFM56-3B1 and-3B2 turbofan engines. That 
action proposed to require initial and repetitive fan blade 
inspections. That proposed AD resulted 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.
    Since we issued the proposed AD, we discovered that we need to make 
some changes to reduce the initial inspection compliance threshold, to 
correct the engine model designations affected, and to clarify some of 
the inspection wording in the compliance section of the proposed AD.

Comments

    We provided the public the opportunity to participate in the 
development of that proposed AD. We have considered the comments 
received.

Request to Correct the Engine Model Designations Affected

    One commenter, CFM International, S.A., requests that we correct 
the engine model designations affected. The commenter states that the 
proposed AD models of CFM56-3B1 and -3B2 are incorrect and should be 
changed to CFM56-3-B1 and -3B-2.
    We partially agree. We agree that we listed incorrect model 
designations. We corrected them in this supplemental NPRM to agree with 
the CFM56 Type Certificate Data Sheet E2GL title block, which lists the 
affected models as CFM56-3 and -3B. We do not agree that the model 
designations should be solely listed as CFM56-3-B1 and -3B-2. However, 
because CFM International, S.A. has added to the basic engine model 
number on the engine nameplate to identify minor variations in engine 
configuration, installation components, or reduced ratings peculiar to 
aircraft installation requirements, engine models CFM56-3-B1 and CFM56-
3B-2 are also affected by this proposed AD.

Request To Add an Installation Prohibition

    CFM International, S.A. requests that we add an installation 
prohibition to our proposed AD applicability, that the installation of 
25 degrees midspan shroud fan blades is not allowed on the CFM56-3C 
engine model.
    We do not agree. The applicability is clear that the proposed AD 
does not include the -3C engine model, as it does not list that model. 
We did not change the NPRM.

Request To Change the Initial Inspection Threshold

    CFM International, S.A. requests that we change the initial 
inspection threshold from 3,000 cycles-in-service (CIS) to within 3 to 
6 months of AD issuance to better harmonize our compliance with 
European Aviation Safety Agency AD 2009-036 (3 months) or with CFM 
International, S.A. CFM56-3/3B/3C S/B 72-1067, dated February 15, 2007 
(6 months).
    We do not agree that a 3 to 6 month interval is appropriate, as the 
passage of time without service is unrelated to the progression of the 
unsafe condition. We do agree that the initial inspection threshold of 
3,000 CIS is too long. We reduced the initial inspection threshold to 
900 CIS in the NPRM.

Differences Between the Supplemental NPRM and the Manufacturer's 
Service Information

    CFM International Service Bulletin (SB) No. CFM56-3/3B/3C S/B 72-
1067, dated February 15, 2007, requires an initial inspection within 6 
months. This supplemental NPRM would require the initial inspection 
within 900 CIS after the effective date of the supplemental NPRM. CFM 
International SB No. 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 supplemental NPRM would 
require the repetitive inspection within 3,000 CSLI.

FAA's Determination and Requirements of the Supplemental NPRM

    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 supplemental NPRM would require you to use the service 
information described previously to perform these actions.

Costs of Compliance

    We estimate that this supplemental NPRM 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 supplemental NPRM 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 supplemental NPRM would not have 
federalism implications under Executive Order 13132. This supplemental 
NPRM 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 
regulation:
    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.

[[Page 16363]]

    We prepared a regulatory evaluation of the estimated costs to 
comply with this supplemental NPRM. See the ADDRESSES section for a 
location to examine the regulatory evaluation.

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-2009-0606; 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 May 17, 
2010.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to CFM International, S.A. models CFM56-3 
and -3B 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.
    (d) CFM International, S.A. has added to the basic engine model 
number on the engine nameplate to identify minor variations in 
engine configuration, installation components, or reduced ratings 
peculiar to aircraft installation requirements.
    (e) Those engines marked on the engine data plate as CFM56-3-B1 
are included in this AD as CFM56-3 turbofan engines.
    (f) Those engines marked on the engine data plate as CFM56-3B-2 
are included in this AD as CFM56-3B turbofan engines.

Unsafe Condition

    (g) 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

    (h) 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

    (i) Within 900 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 paragraphs 3.A.(1) through 3.A.(5) or 
paragraphs 3.B.(1) through 3.B.(5) respectively, of the 
Accomplishment Instructions of CFM International Service Bulletin 
(SB) No. CFM56-3/3B/3C S/B 72-1067, dated February 15, 2007.
    (j) If you find out-of-limit wear on at least one fan blade 
platform underside, perform the additional inspections and 
disposition the parts, as specified in paragraphs 3.A.(3) and 
3.A.(5) or paragraphs 3.B.(3) and 3.B.(5) respectively, of the 
Accomplishment Instructions of CFM International SB No. CFM56-3/3B/
3C S/B 72-1067, dated February 15, 2007.
    (k) Thereafter, within intervals not to exceed 3,000 cycles-
since-last inspection, perform an on-wing or in-shop inspection for 
wear. Use paragraphs 3.A.(1) through 3.A.(5) or paragraphs 3.B.(1) 
through 3.B.(5) respectively, of the Accomplishment Instructions of 
CFM International SB No. CFM56-3/3B/3C S/B 72-1067, dated February 
15, 2007.
    (l) If you find wear on at least one fan blade platform 
underside, perform additional inspections and disposition the parts, 
as specified in paragraphs 3.A.(3) and 3.A.(5) or paragraphs 3.B.(3) 
and 3.B.(5) respectively, of the Accomplishment Instructions of CFM 
International SB No. CFM56-3/3B/3C S/B 72-1067, dated February 15, 
2007.

Installation Prohibition

    (m) 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. of the 
Accomplishment Instructions of CFM International SB No. CFM56-3/3B/
3C S/B 72-1067, dated February 15, 2007.

Optional Terminating Action

    (n) 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 (k) of this AD.

Alternative Methods of Compliance

    (o) 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

    (p) Contact Antonio Cancelliere, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
antonio.cancelliere@faa.gov; telephone (781) 238-7751; fax (781) 
238-7199, for more information about this AD.
    (q) 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 
referenced in this AD.
    (r) European Aviation Safety Agency AD 2009-0036, dated February 
20, 2009, also addresses the subject of this AD.

    Issued in Burlington, Massachusetts, on March 19, 2010.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2010-7343 Filed 3-31-10; 8:45 am]
BILLING CODE 4910-13-P
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