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[Federal Register: March 25, 2010 (Volume 75, Number 57)]
[Proposed Rules]               
[Page 14377-14379]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25mr10-15]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-1095; Directorate Identifier 2008-NE-34-AD]
RIN 2120-AA64

 
Airworthiness Directives; Pratt & Whitney (PW) Model PW2037, 
PW2037(M), and PW2040 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 PW Model PW2037, PW2037(M), and PW2040 turbofan engines. This 
proposed AD would require removing erosion damage on fan blades with 
cutback leading edges and restoring the leading edge contour. This 
proposed AD results from reports from PW that fan blade leading edge 
erosion can result in a fan thrust deterioration mode (FTDM) condition, 
which reduces the engine's capability of producing full rated take-off 
thrust. We are proposing this AD to prevent loss of engine thrust from 
an FTDM condition, which could result in an inability to maintain safe 
flight.

DATES: We must receive any comments on this proposed AD by May 24, 
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 Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone 
(860) 565-8770; fax (860) 565-4503.

FOR FURTHER INFORMATION CONTACT: Mark Riley, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
mark.riley@faa.gov; telephone (781) 238-7758; 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-2008-1095; Directorate 
Identifier 2008-NE-34-AD'' in the subject line of your comments. We 
specifically invite

[[Page 14378]]

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 from PW of leading edge erosion on PW2000 
fan blades (LPC STG 1 Blade) with a cutback leading edge, part numbers 
(P/Ns) 1B6531, 1B6231-001, and 1A9031-001 (LPC STG1 Blade Set P/Ns 
1B6521, 1B6221-001, and 1A9721-001). Leading edge erosion can result in 
an FTDM condition. Pratt & Whitney has found evidence of FTDM from 
engine test cell data, and on installed engines from PW2000 engine 
health monitoring data. The FTDM condition can result in an inability 
of the engine to meet full rated take off thrust and maintain safe 
flight.

Relevant Service Information

    We have reviewed and approved the technical contents of PW Alert 
Service Bulletin (ASB) PW2000 A72-729, Revision 1, dated December 8, 
2009, that describes procedures for removing erosion from the leading 
edge of the fan blades, and restoring the leading edge contour.

Differences Between the Proposed AD and the Manufacturer's Service 
Information

    The PW ASB PW2000 A72-729, Revision 1, dated December 8, 2009, 
requires initial compliance by December 1, 2008, for PW2040 engines and 
by March 1, 2009, for PW2037 and PW2037(M) engines. This proposed AD 
would require initial compliance within 500 cycles-in-service after the 
effective date of this proposed AD for PW2037, PW2037(M) and PW2040 
engines.

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 maintenance to restore the leading edge contour 
of PW2000 fan blade P/Ns 1B6531, 1B6231-001, and 1A9031-001 (LPC STG1 
blade set P/Ns 1B6521, 1B6221-001, and 1A9721-001.
    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 480 engines 
installed on airplanes of U.S. registry. We also estimate that it would 
take about 12 work-hours per engine to perform the proposed actions, 
and that the average labor rate is $85 per work-hour. No parts are 
required. Based on these figures, we estimate the total cost of the 
proposed AD to U.S. operators to be $489,600 per year.

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:

Pratt & Whitney: Docket No. FAA-2008-1095; Directorate Identifier 
2008-NE-34-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by May 24, 
2010.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Pratt & Whitney (PW) PW2037, PW2037(M), 
and PW2040 turbofan engines with six or more fan blade

[[Page 14379]]

(LPC STG1 blade), part numbers (P/Ns) 1B6531, 1B6231-001, or 1A9031-
001 (LPC STG1 blade set P/Ns 1B6521, 1B6221-001, and 1A9721-001), 
with a cutback leading edge, installed. These engines are installed 
on, but not limited to, Boeing 757 airplanes.

Unsafe Condition

    (d) This AD results from reports from PW that fan blade leading 
edge erosion can result in a fan thrust deterioration mode (FTDM) 
condition, which reduces the engine's capability of producing full 
rated take-off thrust. We are issuing this AD to prevent loss of 
engine thrust from an FTDM condition, which could result in an 
inability to maintain safe flight.

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.

Restoring the Fan Blade Leading Edge Contour

    (f) Within 500 cycles-in-service after the effective date of 
this AD, restore the fan blade leading edge contour using one of the 
following:
    (1) For engines installed on the airplane, use the 
Accomplishment Instructions, For Engines Installed on Aircraft, 
paragraphs 1. through 1.T. of PW Alert Service Bulletin (ASB) PW2000 
A72-729, Revision 1, dated December 8, 2009.
    (2) For engines that are not installed on the airplane, use the 
Accomplishment Instructions, For Engines Not Installed on Aircraft, 
paragraphs 1. through 1.S. of PW ASB PW2000 A72-729, Revision 1, 
dated December 8, 2009.
    (g) Thereafter, repeat paragraphs (f)(1) or (f)(2) of this AD, 
within intervals of 1,000 cycles-since-last repair.

Alternative Methods of Compliance

    (h) Pratt & Whitney PW2037, PW2040, PW2240, PW2337 Turbofan 
Engine Manual, Part No. 1A6231, Chapter/Section 72-31-12, Repair 14, 
is an approved alternative method of compliance to paragraphs (f)(1) 
and (f)(2) of this AD.
    (i) Boeing 757 Airplane Flight Manual Document D631N002, 
Appendix 24, (Performance For Operation Of PW2000 Series Engines 
With Cutback Fan Blades Installed), is an approved alternative 
method of compliance to paragraphs (f)(1) and (f)(2) and (g) of this 
AD.
    (j) 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

    (k) Contact Mark Riley, Aerospace Engineer, Engine Certification 
Office, FAA, Engine and Propeller Directorate, 12 New England 
Executive Park, Burlington, MA 01803; e-mail: mark.riley@faa.gov; 
telephone (781) 238-7758, fax (781) 238-7199, for more information 
about this AD.
    (l) Pratt & Whitney ASB PW2000 A72-729, Revision 1, dated 
December 8, 2009, pertains to the subject of this AD. Contact Pratt 
& Whitney, 400 Main St., East Hartford, CT 06108; telephone (860) 
565-8770; fax (860) 565-4503, for a copy of this service 
information.

    Issued in Burlington, Massachusetts, on March 18, 2010.
Francis A. Favara,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.

[FR Doc. 2010-6583 Filed 3-24-10; 8:45 am]
BILLING CODE 4910-13-P
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