Document ID: FAA-2008-1245-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; CFM International S.A. Model CFM56 Turbofan Engines
Posted Date: 2008-11-26T05:00Z

[Federal Register: November 26, 2008 (Volume 73, Number 229)]
[Proposed Rules]               
[Page 71951-71952]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr26no08-27]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-1245; Directorate Identifier 2008-NE-27-AD]
RIN 2120-AA64

 
Airworthiness Directives; CFM International S.A. Model CFM56 
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. CFM56-2, CFM56-3, CFM56-5A, CFM56-5B, CFM56-
5C, and CFM56-7B series turbofan engines with certain part number (P/N) 
and serial number (SN) high-pressure compressor (HPC) 4-9 spools 
installed. This proposed AD would require removing certain HPC 4-9 
spools listed by P/N and SN in this proposed AD. This proposed AD 
results from reports of certain HPC 4-9 spools that Propulsion 
Technology LLC (PTLLC) improperly repaired and returned to service. We 
are proposing this AD to prevent cracking of the HPC 4-9 spool, which 
could result in possible uncontained failure of the spool and damage to 
the airplane.

DATES: We must receive any comments on this proposed AD by January 26, 
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: 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-2008-1245; Directorate 
Identifier 2008-NE-27-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

    We have received reports of life-limited parts (LLPs) HPC 4-9 
spools that PTLLC, repair station certificate No. XZ4R084M, improperly 
repaired and returned to service. Our investigation found some areas of 
the seal tooth plasma coating that were thicker than allowed by the 
CFM56 engine overhaul limits. The investigation also found:
     Seal tooth plasma overspray between the seal teeth, which 
is not permitted by the engine overhaul manual, and
     Cracks that were missed during the fluorescent penetrant 
inspection.
    These conditions, if not corrected, could cause cracking of the HPC 
4-9 spool, which could result in possible uncontained failure of the 
spool and damage to the airplane.

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 
removing certain HPC 4-9 spools that have a P/N and SN listed in Table 
1 of this proposed AD before accumulating 8,900 cycles since repair at 
PTLLC or within 1,100 cycles from the effective date of this AD, 
whichever occurs later.

Costs of Compliance

    We estimate that this proposed AD would affect 26 engines installed 
on airplanes of U.S. registry. We also estimate that it would take 
about 410 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 $227,500 per engine. Based on these figures, we estimate the 
total cost of the proposed AD to U.S. operators to be $6,767,800.

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.

[[Page 71952]]

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-2008-1245; Directorate 
Identifier 2008-NE-27-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by January 26, 
2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to CFM International S.A. CFM56-2, CFM56-3, 
CFM56-5A, CFM56-5B, CFM56-5C, and CFM56-7B series turbofan engines 
with a high-pressure compressor (HPC) 4-9 spool that has a part 
number (P/N) and serial number (SN) specified in Table 1 of this AD, 
installed. These engines are installed on, but not limited to, 
Airbus A319, A320, and A340 airplanes and Boeing 737 airplanes.

                  Table 1--HPC 4-9 Spools by P/N and SN
------------------------------------------------------------------------
             HPC 4-9 Spool P/N                    HPC 4-9 Spool SN
------------------------------------------------------------------------
9513M93G08................................  MPON1641
1590M29G01................................  GWN0087D
1590M29G01................................  GWN00MG2
1590M29G01................................  GWN011LG
1590M29G01................................  GWN01285
1590M29G01................................  GWN021JC
1590M29G01................................  GWNFY923
1590M29G01................................  GWNFY824
1590M29G01................................  GWNPA756
1590M29G01................................  GWNPG015
1590M29G01................................  GWNWC515
1590M29G01................................  GWNWR523
1590M29G01................................  GWNWT631
1590M29G01................................  GWNYC495
1588M89G03................................  GWN03K1R
1588M89G03................................  GWN03N61
1588M89G03................................  GWN03N6C
1588M89G03................................  GWN040L9
1588M89G03................................  GWN0468N
1588M89G03................................  GWN05AMO
1277M97G02................................  GWNE1298
1277M97G02................................  GWNE1564
1277M97G02................................  GWNJ7891
1277M97G02................................  GWNT4187
9513M93G11................................  GWNB3373
1358M94G01................................  GWNU0169
------------------------------------------------------------------------

Unsafe Condition

    (d) This AD results from reports of certain HPC 4-9 spools that 
Propulsion Technology LLC (PTLLC) improperly repaired and returned 
to service. We are issuing this AD to prevent cracking of the HPC 4-
9 spool, which could result in possible uncontained failure of the 
spool 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.

Removing the HPC 4-9 Spool

    (f) Remove HPC 4-9 spools from service that have a P/N and S/N 
listed in Table 1 of this AD before accumulating 8,900 cycles since 
repair at PTLLC or within 1,100 cycles from the effective date of 
this AD, whichever occurs later.

Installation Prohibition

    (g) After the effective date of this AD, do not install any 
engine with an HPC 4-9 spool that has a P/N and SN specified in 
Table 1 of this AD.

Alternative Methods of Compliance

    (h) 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

    (i) 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.

    Issued in Burlington, Massachusetts, on November 18, 2008.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E8-28055 Filed 11-25-08; 8:45 am]

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