Document ID: FAA-2012-0546-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Pratt and Whitney Division Turbofan Engines
Posted Date: 2012-07-11T04:00Z

[Federal Register Volume 77, Number 133 (Wednesday, July 11, 2012)]
[Proposed Rules]
[Pages 40822-40823]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-16857]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0546; Directorate Identifier 2012-NE-15-AD]
RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney Division Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for all 
Pratt & Whitney PW4050, PW4052, PW4056, PW4060, PW4060A, PW4060C, 
PW4062, PW4062A, PW4152, PW4156, PW4156A, PW4158, PW4160, PW4460, 
PW4462, and PW4650 turbofan engines, including models with any dash 
number suffix. This proposed AD was prompted by 16 reports of damaged 
or failed 3rd stage low-pressure turbine (LPT) duct segments. This 
proposed AD would require removing from service certain part numbers 
(P/Ns) of 3rd stage LPT duct segments. We are proposing this AD to 
prevent failure of the 3rd stage LPT duct segments, which could lead to 
LPT rotor damage, uncontained engine failure, and damage to the 
airplane.

DATES: We must receive comments on this proposed AD by September 10, 
2012.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Pratt & Whitney, 400 Main St., East Hartford, CT 06108; phone: 860-565-
8770; fax: 860-565-4503. You may review copies of the referenced 
service information at the FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA. For information on the 
availability of this material at the FAA, call 781-238-7125.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility 
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 Office (phone: 800-647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.

FOR FURTHER INFORMATION CONTACT: James Gray, Aerospace Engineer, Engine 
& Propeller Directorate, FAA, 12 New England Executive Park, 
Burlington, MA 01803; phone: 781-238-7742; fax: 781-238-7199; email: 
james.e.gray@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2012-0546; 
Directorate Identifier 2012-NE-15-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because 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 we 
receive about this proposed AD.

Discussion

    We received 16 reports of damaged or failed 3rd stage LPT duct 
segments that resulted in 5 in-flight shutdowns, two of which were 
uncontained engine failures. The 3rd stage LPT duct segment assembly 
has seal plates that are attached with rivets. During normal engine 
operation, vibration may cause these seal plates to loosen or fall off, 
which allows hot gaspath air to enter the cavity behind the duct. This 
can cause the 3rd stage LPT duct segment to distort, fall into the 
gaspath, and damage the downstream LPT rotor blades. This condition, if 
not corrected, could result in failure of the 3rd stage LPT duct 
segments, which could lead to LPT rotor damage, uncontained engine 
failure, and damage to the airplane.

Relevant Service Information

    We reviewed Pratt & Whitney Engine-Duct Segment, Third Stage LPT 
Assembly Service Bulletin (SB) No. PW4ENG 72-488, Revision 3, dated 
August 13, 2009. The SB lists the part numbers of parts to be removed 
and parts to be installed.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This proposed AD would require removal from service of 3rd stage 
LPT duct segments P/Ns 50N095; 50N095-001; 50N235; 50N235-001; 50N494-
01; 50N494-001; 50N495-01; and 50N495-001, at the next piece-part 
exposure after the effective date of the proposed AD.

Costs of Compliance

    We estimate that this proposed AD would affect 151 engines 
installed on airplanes of U.S. registry. We estimate that no additional 
labor costs would be incurred to perform the required work as the work 
is done when the 3rd stage LPT duct segments are at piece-part 
exposure. The average labor rate is $85 per work-hour. Required parts 
would cost about $44,441 per engine. Based on these figures, we 
estimate the total cost of the AD to U.S. operators to be $6,710,591.

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.

[[Page 40823]]

    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 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 this 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),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA 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 (AD):

Pratt & Whitney Division: Docket No. FAA-2012-0546; Directorate 
Identifier 2012-NE-15-AD.

(a) Comments Due Date

    We must receive comments by September 10, 2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Pratt & Whitney PW4050, PW4052, PW4056, 
PW4060, PW4060A, PW4060C, PW4062, PW4062A, PW4152, PW4156, PW4156A, 
PW4158, PW4160, PW4460, PW4462, and PW4650 turbofan engines, 
including models with any dash number suffix, with 3rd stage LPT 
duct segments P/N 50N095; 50N095-001; 50N235; 50N235-001; 50N494-01; 
50N494-001; 50N495-01; or 50N495-001, installed.

(d) Unsafe Condition

    This AD was prompted by 16 reports of damaged or failed 3rd 
stage low-pressure turbine (LPT) duct segments. We are issuing this 
AD to prevent failure of the 3rd stage LPT duct segments, which 
could lead to LPT rotor damage, uncontained engine failure, and 
damage to the airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(f) 3rd Stage LPT Duct Segments Removal From Service

    At the next piece-part exposure after the effective date of this 
AD, remove from service 3rd stage LPT duct segments, P/Ns 50N095; 
50N095-001; 50N235; 50N235-001; 50N494-01; 50N494-001; 50N495-01; 
and 50N495-001.

(g) Installation Prohibition

    After the effective date of this AD, do not install into any 
engine any 3rd stage LPT duct segment, P/N 50N095; 50N095-001; 
50N235; 50N235-001; 50N494-01; 50N494-001; 50N495-01; or 50N495-001, 
that is at piece-part exposure.

(h) Definition

    For the purpose of this AD, piece-part exposure is when the 3rd 
stage LPT duct segment is removed from the engine and completely 
disassembled.

(i) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, may approve AMOCs for 
this AD. Use the procedures found in 14 CFR 39.19 to make your 
request.

(j) Related Information

    (1) Pratt & Whitney Engine-Duct Segment, Third Stage LPT 
Assembly Service Bulletin (SB) No. PW4ENG 72-488, Revision 3, dated 
August 13, 2009.
    (2) For more information about this AD, contact James Gray, 
Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New 
England Executive Park, Burlington, MA 01803; phone: 781-238-7742; 
fax: 781-238-7199; email: james.e.gray@faa.gov.
    (3) For service information identified in this AD, contact Pratt 
& Whitney, 400 Main St., East Hartford, CT 06108; phone: 860-565-
8770; fax: 860-565-4503. You may review copies of the service 
information at the FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA. For information on the 
availability of this material at the FAA, call 781-238-7125.

    Issued in Burlington, Massachusetts, on July 2, 2012.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-16857 Filed 7-10-12; 8:45 am]
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