Document ID: FAA-2011-0733-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Pratt and Whitney Division PW4000 Series Turbofan Engines
Posted Date: 2011-07-14T04:00Z

[Federal Register Volume 76, Number 135 (Thursday, July 14, 2011)]
[Proposed Rules]
[Pages 41430-41432]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-17648]

 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 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.
 
 ========================================================================
 

  Federal Register / Vol. 76, No. 135 / Thursday, July 14, 2011 / 
Proposed Rules  

[[Page 41430]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0733; Directorate Identifier 2010-NE-36-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).

-----------------------------------------------------------------------

SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain PW4000 turbofan engines. This proposed AD was prompted by an 
updated low-cycle fatigue (LCF) life analysis performed by Pratt & 
Whitney. This proposed AD would require removing certain part number 
(P/N) high-pressure turbine (HPT) stage 1 and HPT stage 2 airseals and 
HPT stage 1 airseal rings before their published life limit, and 
establishes a new lower life limit for these parts. We are proposing 
this AD to correct the unsafe condition on these products.

DATES: We must receive comments on this proposed AD by August 29, 2011.

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.

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; e-mail: 
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-2011-0733; 
Directorate Identifier 2010-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

    A PW2000 field event led Pratt & Whitney to re-evaluate the low-
cycle fatigue (LCF) lives of its PW2000 engine, and similar engines 
models, including the PW4000 engine and its high-pressure turbine 
(HPT). Pratt and Whitney's updated analysis indicated that the current 
certified life limits for the PW4000 HPT stage 1 and stage 2 air seals 
and air seal rings should be reduced to prevent failure of those life 
limited parts. The current certified life limits, if not reduced, 
present an unacceptable level of risk of part failure. This condition, 
if not corrected, could result in 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 removing the HPT stage 1 airseal, P/
N 50L879; the HPT stage 2 airseal, P/N 53L030; and the HPT airseal 
ring, P/N 50L664, prior to their published life limits, using a 
drawdown plan.

Costs of Compliance

    We estimate that this proposed AD would affect 869 engines 
installed on airplanes of U.S. registry. We also estimate that, because 
the removals would be performed at piece-part level, no additional 
work-hours would be required. Prorated life for the HPT would be about 
$46,835 per engine. Based on these figures, we estimate the total cost 
of the proposed AD to U.S. operators to be $40,699,615.

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 proposed AD would not 
have a

[[Page 41431]]

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, 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-2011-0733; Directorate 
Identifier 2010-NE-36-AD.

(a) Comments Due Date

    We must receive comments by August 29, 2011.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to the following Pratt & Whitney Division (PW) 
turbofan engines, with high-pressure turbine (HPT) stage 1 airseal, 
part number (P/N) 50L879; HPT stage 2 airseal, P/N 53L030; or HPT 
stage 1 airseal ring, P/N 50L664, installed:

(1) PW4000-100'' Engines

    PW4000-100'' engine models PW4164, PW4164C, PW4164C/B, PW4168, 
and PW4168A.

(2) PW4000-94'' Engines

    (i) PW4000-94'' engine models PW4060, PW4060A, PW4060C, PW4062, 
PW4062A, PW4156A, PW4158, PW4160, PW4460, and PW4462 engines that 
have incorporated Pratt & Whitney Service Bulletins (SBs) PW4ENG 72-
490, or PW4ENG 72-504, or PW4ENG 72-512, or PW4ENG 72-572, or PW4ENG 
72-588, or PW4ENG 73-150, or Engineering Change Number EC92KK322G, 
H, I, J, and K, as indicated with a (-3), or (-3A), or (-3B) suffix 
on the engine data plate.
    (ii) PW4000-94'' engines models PW4050, PW4052, PW4056, PW4152, 
PW4156, and PW4650 engines that have incorporated Pratt & Whitney 
SBs PW4ENG 72-490, or PW4ENG 72-504, or PW4ENG 72-512, or PW4ENG 72-
572, or PW4ENG 72-588, or PW4ENG 73-150, or Engineering Change 
Number EC92KK322G, H, I, J, and K, as indicated with a (-3), or (-
3A), or (-3B) suffix on the engine data plate.

(d) Unsafe Condition

    This AD was prompted by an updated low-cycle fatigue (LCF) life 
analysis performed by Pratt & Whitney. We are issuing this AD to 
correct the unsafe condition on these products.

(e) Compliance

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

(f) Removing From Service, the Stage 1 HPT Airseal, P/N 50L879

    Remove the stage 1 HPT airseal, P/N 50L879, at the next piece-
part exposure after the effective date of this AD, or before 
accumulating the number of cycles listed in Table 1 of this AD, 
whichever occurs later.

 Table 1--Removal of Stage 1 HPT Airseals, P/N 50L879, by Cycles-Since-
                                   New
------------------------------------------------------------------------
                                              Remove stage 1 HPT Airseal
           For engine model . . .                      by . . .
------------------------------------------------------------------------
(1) Listed in paragraph (c)(1) of the        12,600 cycles-since-new
 Applicability Section of this AD.            (CSN).
(2) Listed in paragraph (c)(2)(i) of the     13,900 CSN.
 Applicability Section of this AD.
(3) Listed in paragraph (c)(2)(ii) of the    18,900 CSN.
 Applicability Section of this AD.
------------------------------------------------------------------------

(g) Removing From Service, the Stage 2 HPT Airseal, P/N 53L030

    Remove the stage 2 HPT airseal, P/N 53L030, at the next piece-
part exposure after the effective date of this AD, or before 
accumulating the number of cycles listed in Table 2 of this AD, 
whichever occurs later.

 Table 2--Removal of Stage 2 HPT Airseals, P/N 53L030, by Cycles-Since-
                                   New
------------------------------------------------------------------------
                                                   Remove stage 2 HPT
            For engine model . . .                 Airseal  by . . .
------------------------------------------------------------------------
(1) Listed in paragraph (c)(1) of the          13,900 CSN.
 Applicability Section of this AD.
(2) Listed in paragraph (c)(2)(i) of the       13,800 CSN.
 Applicability Section of this AD.
(3) Listed in paragraph (c)(2)(ii) of the      15,900 CSN.
 Applicability Section of this AD.
------------------------------------------------------------------------

(h) Removing From Service, the Stage 1 HPT Airseal Ring, P/N 50L664

    Remove the stage 1 HPT airseal ring, P/N 50L664, at the next 
piece-part exposure after the effective date of this AD, or before 
accumulating the number of cycles listed in Table 3 of this AD, 
whichever occurs later.

[[Page 41432]]

  Table 3--Removal of Stage 1 HPT Airseal Ring, P/N 50L664, by Cycles-
                                Since-New
------------------------------------------------------------------------
                                                   Remove stage 1 HPT
            For engine model . . .               Airseal Ring by . . .
------------------------------------------------------------------------
(1) Listed in paragraph (c)(2)(i) of the       14,800 CSN.
 Applicability Section of this AD.
(2) Listed in paragraph (c)(2)(ii) of the      16,800 CSN.
 Applicability Section of this AD.
------------------------------------------------------------------------

(i) Installation Prohibition

    After the effective date of this AD, do not install any stage 1 
HPT airseal, P/N 50L879, stage 2 HPT airseal, P/N 53L030, or stage 1 
HPT airseal ring, P/N 50L664, that is at piece-part exposure and 
exceeds the new life limit listed in Table 1, Table 2, or Table 3, 
respectively, of this AD.

(j) Definitions

    For the purpose of this AD, piece-part exposure means that the 
part is completely disassembled and removed from the engine.

(k) Alternative Methods of Compliance (AMOCs)

    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.

(l) Related Information

    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; e-mail: james.e.gray@faa.gov.

    Issued in Burlington, Massachusetts, on July 8, 2011.
Peter A. White,
Acting Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-17648 Filed 7-13-11; 8:45 am]
BILLING CODE 4910-13-P