Document ID: FAA-2011-0944-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Pratt and Whitney Division (PW) PW4000 Series Turbofan Engines
Posted Date: 2011-11-07T05:00Z

[Federal Register Volume 76, Number 215 (Monday, November 7, 2011)]
[Proposed Rules]
[Pages 68660-68661]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-28676]

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 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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  Federal Register / Vol. 76, No. 215 / Monday, November 7, 2011 / 
Proposed Rules  

[[Page 68660]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0944; Directorate Identifier 2011-NE-11-AD]
RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney Division (PW) PW4000 
Series 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 
PW4000 series turbofan engines. This proposed AD would require 
replacing the fuel metering unit (FMU), part number (P/N) 50U150, at 
the next shop visit after the effective date of this proposed AD. This 
proposed AD was prompted by an engine overspeed event that occurred 
during taxi and resulted in a high-pressure compressor (HPC) surge and 
tailpipe fire. We are proposing this AD to prevent engine overspeed on 
these engines, which could result in an uncontained engine failure and 
damage to the airplane.

DATES: We must receive comments on this proposed AD by January 6, 2012.

ADDRESSES: You may send comments 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. You may review copies of the referenced service information 
at the FAA, Engine & Propeller Directorate, 12 New England Executive 
Park, Burlington, MA 01803. 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 
Certification Office, 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-2011-0944; 
Directorate Identifier 2011-NE-11-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 a report of an engine overspeed during taxi, which 
resulted in an HPC surge and tailpipe fire. Although the event was not 
an uncontained engine failure, engine overspeed events compromise the 
integrity of the rotor and can lead to an uncontained engine failure. 
Our investigation concluded that the existing FMU is susceptible to a 
single-point failure condition in which a complete or nearly complete 
blockage of the FMU servo wash filter could occur. A blockage in the 
FMU servo wash filter could result in insufficient hydraulic pressure 
being available to properly control the FMU and actuator functions. 
Inability to control the FMU and actuator functions, if not corrected, 
could result in an engine overspeed and an uncontained engine failure 
and damage to the airplane.

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 replacing the FMU, P/N 50U150, at 
the next shop visit after the effective date of this proposed AD.

Costs of Compliance

    We estimate that this proposed AD affects 750 engines installed on 
airplanes of U.S. registry. We also estimate that it would take about 
3.2 work-hours per product to comply with this proposed AD. The average 
labor rate is $85 per work-hour. Required parts would cost about 
$10,698 per engine. Based on these figures, we estimate the cost of the 
proposed AD on U.S. operators to be $8,227,500.

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

[[Page 68661]]

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 (PW): Docket No. FAA-2011-0944; Directorate 
Identifier 2011-NE-11-AD.

Comments Due Date

    (a) We must receive comments by January 6, 2012.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all PW 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.

Unsafe Condition

    (d) This AD was prompted by an engine overspeed event that 
occurred during taxi and resulted in a high-pressure compressor 
surge and tailpipe fire. We are issuing this AD to prevent engine 
overspeed on these engines, which could result in an uncontained 
engine failure and damage to the airplane.

Compliance

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

Replacement of Fuel Metering Unit (FMU), Part Number (P/N) 50U150

    (f) At the next shop visit after the effective date of this AD, 
remove FMU, P/N 50U150, and install an FMU that has been modified as 
specified in paragraphs 2.A through 2.C of the Accomplishment 
Instructions of PW Alert Service Bulletin PW4ENG A73-220, Revision 
1, dated May 18, 2011.

Installation Prohibition

    (g) Three years from the effective date of this AD, do not 
install FMU, P/N 50U150, onto any engine.

Definition of Shop Visit

    (h) For the purpose of this AD, a shop visit is when the engine 
is inducted into the shop for any maintenance involving the 
separation of pairs of major mating engine flanges (lettered 
flanges). However, the separation of engine flanges solely for the 
purposes of transporting the engine without subsequent engine 
maintenance is not an engine shop visit.

Alternative Methods of Compliance (AMOCs)

    (i) The Manager, Engine Certification Office, FAA, has the 
authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19.

Related Information

    (j) For more information about this AD, contact James Gray, 
Aerospace Engineer, Engine Certification Office, FAA, 12 New England 
Executive Park, Burlington, MA 01803; phone: (781) 238-7742; fax: 
(781) 238-7199; email: james.e.gray@faa.gov.
    (k) For service information identified in this AD, contact Pratt 
& Whitney, 400 Main St., East Hartford, CT 06108; phone: (860) 565-
8770. You may review copies of the referenced service information at 
the FAA, Engine & Propeller Directorate, 12 New England Executive 
Park, Burlington, MA 01803. For information on the availability of 
this material at the FAA, call (781) 238-7125.

    Issued in Burlington, Massachusetts, on October 31, 2011.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-28676 Filed 11-4-11; 8:45 am]
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