Document ID: FAA-2011-1194-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Pratt and Whitney Turbofan Engines
Posted Date: 2011-11-23T05:00Z

[Federal Register Volume 76, Number 226 (Wednesday, November 23, 2011)]
[Proposed Rules]
[Pages 72353-72355]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-30138]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-1194; Directorate Identifier 2011-NE-36-AD]
RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney 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

[[Page 72354]]

& Whitney PW4050, PW4052, PW4056, PW4056(-3), PW4156, PW4060, PW4060(-
3), PW4060A, PW4152, PW4152(-3), PW4156A, PW4158, PW4158(-3), PW4460, 
PW4460(-3), PW4462, and PW4462(-3) turbofan engines. This proposed AD 
was prompted by reports of five engine in-flight shutdowns and seven 
unplanned engine removals. This proposed AD would require inspections, 
cleaning, and engine modifications to address coking in the No. 4 
bearing compartment and oil pressure and scavenge tubes. We are 
proposing this AD to prevent an engine fire, a fractured fan drive 
shaft, and damage to the airplane.

DATES: We must receive comments on this proposed AD by January 23, 
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: Stephen Sheely, Aerospace Engineer, 
Engine & Propeller Directorate, FAA, 12 New England Executive Park, 
Burlington, MA 01803; phone: (781) 238-7750; fax: (781) 238-7199; 
email: stephen.k.sheely@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-2011-1194; 
Directorate Identifier 2011-NE-36-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 reports of five engine in-flight shutdowns and seven 
unplanned engine removals due to clogging of No. 4 bearing compartment 
oil pressure and scavenge tubes. Investigation has revealed that 
following all engine shutdowns, excessive heat is conducting into the 
No. 4 bearing compartment and into the oil pressure and scavenge tubes 
that pass through the turbine exhaust case struts. This excessive heat 
causes oil coking and oil flow restriction in the pressure and scavenge 
tubes and oil nozzle. This condition, if not corrected, could lead to 
an engine fire, a fractured fan drive shaft, and damage to the 
airplane.

Relevant Service Information

    We reviewed Pratt & Whitney Alert Service Bulletin (SB) No. PW4ENG-
A72-436, Revision 6, dated September 30, 1999. The SB describes 
procedures for initial and repetitive inspection and cleaning of the 
No. 4 bearing compartment. We also reviewed Pratt & Whitney SB No. 
PW4ENG-72-472, Revision 5, dated April 14, 1998, and SB No. PW4ENG-79-
76, Revision 4, dated February 14, 2002. The SBs describe procedures 
for modifications to stop buildup of coking in the No. 4 bearing 
compartment, and for rerouting of the No. 4 bearing pressure and 
scavenge tubes. The rerouted tubes are then located below the engine 
centerline which eliminates the coking problem.

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 accomplishing the actions specified 
in the service information described previously.

Costs of Compliance

    We estimate that this proposed AD would affect 44 Pratt & Whitney 
PW4050, PW4052, PW4056, PW4056(-3), PW4156, PW4060, PW4060(-3), 
PW4060A, PW4152, PW4152(-3), PW4156A, PW4158, PW4158(-3), PW4460, 
PW4460(-3), PW4462, and PW4462(-3) turbofan engines installed on 
airplanes of U.S. registry. We also estimate that it would take about 8 
work-hours per engine to perform an inspection and cleaning of the No. 
4 bearing compartment, about 7 work-hours per engine to perform the 
modification to stop buildup of coking in the No. 4 bearing 
compartment, and about 33.7 work-hours per engine to perform the 
rerouting of the No. 4 bearing pressure and scavenge tubes. The average 
labor rate is $85 per work-hour. Required parts would cost about 
$69,322 per engine. Based on these figures, we estimate the total cost 
of the AD to U.S. operators to be $3,232,306.

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 determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This

[[Page 72355]]

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: Docket No. FAA-2011-1194; Directorate Identifier 
2011-NE-36-AD.

(a) Comments Due Date

    We must receive comments by January 23, 2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Pratt & Whitney PW4050, PW4052, PW4056, 
PW4056(-3), PW4156, PW4060, PW4060(-3), PW4060A, PW4152, PW4152(-3), 
PW4156A, PW4158, PW4158(-3), PW4460, PW4460(-3), PW4462, and 
PW4462(-3) turbofan engines.

(d) Unsafe Condition

    This AD was prompted by reports of five engine in-flight 
shutdowns and seven unplanned engine removals due to clogging of No. 
4 bearing compartment oil pressure and scavenge tubes. We are 
issuing this AD to prevent an engine fire, a fractured fan drive 
shaft, and damage to the airplane.

(e) Compliance

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

(f) Inspection and Cleaning of No. 4 Bearing Compartment for Coking

    (1) Within 1,000 cycles-in-service (CIS) after the effective 
date of this AD, initially inspect and clean the No. 4 bearing 
compartment in accordance with Accomplishment Instructions, 
paragraphs 2.A. through 2.A.(4)(b)3 of Pratt & Whitney Alert Service 
Bulletin No. PW4ENG-A72-436, Revision 6, dated September 30, 1999.
    (2) Thereafter, within every additional 1,000 CIS, perform the 
inspection and cleaning specified in paragraph (f)(1) of this AD.

(g) Modification To Stop Buildup of Coking in the No. 4 Bearing 
Compartment

    (1) At the next engine visit to a maintenance facility that is 
capable of performing the following on-wing method or in-shop method 
of modification to the No. 4 bearing compartment, but not to exceed 
5 years after the effective date of this AD, do the following:
    (i) Replace the No. 4 bearing packing transfer tube assembly;
    (ii) Replace the No. 4 bearing internal scavenge tube assembly;
    (iii) Remove the No. 4 bearing shield, and the No. 4 bearing 
shield option; and
    (iv) Install new No. 4 bearing shield options.
    (2) For doing the on-wing method of the modification, do the 
work in accordance with Accomplishment Instructions, Paragraphs 2.A. 
through 2.A.(9)(a)3d of Pratt & Whitney Service Bulletin (SB) No. 
PW4ENG-72-472, Revision 5, dated April 14, 1998.
    (3) For doing the in-shop method of the modification, do the 
work in accordance with Paragraphs 2.B. through 2.B.(2)(f)2d of 
Pratt & Whitney SB No. PW4ENG-72-472, Revision 5, dated April 14, 
1998.

(h) Rerouting of the No. 4 Bearing Pressure and Scavenge Tubes

    (1) At the next shop visit at which the engine is sufficiently 
disassembled to perform the rerouting, but not to exceed 5 years 
after the effective date of this AD, do the following:
    (i) Modify the turbine exhaust case to relocate the No. 4 
bearing pressure and scavenge tube ports;
    (ii) Replace the internal No. 4 bearing pressure and scavenge 
tubes;
    (iii) Modify or replace the turbine case cooling brackets to 
support the new No. 4 bearing pressure and scavenge tubes;
    (iv) Replace the turbine case manifolds as necessary; and
    (v) Install the new brackets and clamps to support the new 
routing configuration.
    (2) Do the work specified in paragraph (h) of this AD in 
accordance with Accomplishment Instructions paragraph 2 of Pratt & 
Whitney SB No. PW4ENG-79-76, Revision 4, dated February 14, 2002.

(i) Terminating Action to the Repetitive Inspections and Cleaning

    Performing the modifications specified in both paragraphs (g) 
and (h), of this AD is terminating action to the repetitive 
inspections and cleanings specified in paragraph (f)(2) of this AD.

(j) 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.

(k) Related Information

    (1) For more information about this AD, contact Stephen Sheely, 
Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New 
England Executive Park, Burlington, MA 01803; phone: (781) 238-7750; 
fax: (781) 238-7199; email: stephen.k.sheely@faa.gov.
    (2) For service information identified in this AD, contact Pratt 
& Whitney, 400 Main St., East Hartford, CT 06108; telephone: (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.

    Issued in Burlington, Massachusetts, on November 15, 2011.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-30138 Filed 11-22-11; 8:45 am]
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