[Federal Register Volume 76, Number 234 (Tuesday, December 6, 2011)]
[Rules and Regulations]
[Pages 76027-76029]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-31177]



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  Federal Register / Vol. 76, No. 234 / Tuesday, December 6, 2011 / 
Rules and Regulations  

[[Page 76027]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0733; Directorate Identifier 2010-NE-36-AD; 
Amendment 39-16885; AD 2011-25-09]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Division (PW) PW4000 
Series Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
PW4000 turbofan engines. This AD was prompted by an updated low-cycle 
fatigue (LCF) life analysis performed by PW. This AD requires 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 issuing this AD to prevent failure of these parts, which could lead 
to an uncontained engine failure and damage to the airplane.

DATES: This AD is effective January 10, 2012.

ADDRESSES: For service information identified in this AD, contact Pratt 
& Whitney, 400 Main St., East Hartford, CT 06108; phone: (860) 565-
1605. 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 AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (phone: (800) 647-5527) is Document Management Facility, 
U.S. Department of Transportation, Docket Operations, M-30, West 
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: James Gray, Aerospace Engineer, Engine 
Certification Office, FAA, 12 New England Executive Park; phone: (781) 
238-7742; fax: (781) 238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM published in the Federal Register on July 14, 2011 (76 FR 
41430). That NPRM proposed to require removing certain P/N 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.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the proposal 
and the FAA's response to each comment.

Request To Publish Date When Chapter 5 Will Be Revised

    One commenter, Lufthansa Technik AG (Lufthansa), requested that we 
note in the AD that Chapter 5 will be revised and indicate when it will 
occur. Lufthansa believes this knowledge will help optimize planning 
for removal of parts that will be close to their reduced life limits 
when Chapter 5 is revised.
    We do not agree. Although Chapter 5 may be revised in the future, 
we do not know when. If Chapter 5 is revised in the future, we will 
publish an NPRM that will allow the public an opportunity to comment. 
We did not change the AD as a result of this comment.

Request To Indicate How To Perform Pro-Rata Calculation

    One commenter, SR Technics, requested that the AD define how to 
perform the pro-rata calculation of the parts' life limit after the 
effective date of the AD for parts that have been installed on engines 
with different thrust loads.
    We do not agree. Information on how to track part life for parts 
that have been installed on engines with different thrust loads can be 
found in the relevant engine manual. We did not change the AD as a 
result of this comment.

Request for Industry Support Program

    One commenter, FedEx Express (FedEx), indicated that the proposed 
AD would affect 174 engines in its fleet and cost FedEx $8,149,290. 
FedEx requested that Pratt & Whitney, therefore, provide an industry 
support program to help alleviate this financial burden.
    We do not agree. We do not have the authority to require a design 
approval holder to offer such a program. We did not change the AD as a 
result of this comment.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
the AD as proposed except for minor editorial changes to the Unsafe 
Condition paragraph made for clarification.
    We have determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM (76 FR 41430, July 14, 2011) for correcting the unsafe condition; 
and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM (76 FR 41430, July 14, 2011).

Costs of Compliance

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

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue

[[Page 76028]]

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

    This AD will not have federalism implications under Executive Order 
13132. This AD will 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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under 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.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2011-25-09 Pratt & Whitney Division: Amendment 39-16885; Docket No. 
FAA-2011-0733; Directorate Identifier 2010-NE-36-AD.

(a) Effective Date

    This AD is effective January 10, 2012.

(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 that have 
incorporated either Engineering Change Numbers EC92KK322G, H, I, J, 
and K, or one of the following PW Service Bulletins (SBs): PW4ENG 
72-490, PW4ENG 72-504, PW4ENG 72-512, PW4ENG 72-572, PW4ENG 72-588, 
PW4ENG 73-150; as indicated with a (-3), (-3A), or (-3B) suffix on 
the engine data plate.
    (ii) PW4000-94'' engine models PW4050, PW4052, PW4056, PW4152, 
PW4156, and PW4650 that have incorporated either Engineering Change 
Numbers EC92KK322G, H, I, J, and K, or one of the following PW SBs: 
PW SB PW4ENG 72-490, PW4ENG 72-504, PW4ENG 72-512, PW4ENG 72-572, 
PW4ENG 72-588, PW4ENG 73-150; as indicated with a (-3), (-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 PW. We are issuing this AD to prevent failure 
of these parts, which could lead to an uncontained engine failure 
and damage to the airplane.

(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 (CSN)
------------------------------------------------------------------------
                                             Remove stage 1 HPT airseal
          For engine model . . .                      by . . .
------------------------------------------------------------------------
(1) Listed in paragraph (c)(1) of the       12,600 CSN.
 Applicability Section of this AD.
(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 CSN
------------------------------------------------------------------------
                                             Remove stage 2 HPT airseal
          For engine model . . .                      by . . .
------------------------------------------------------------------------
(1) Listed in paragraph (c)(1) of the       13,900 CSN.
 Applicability Section of this AD.

[[Page 76029]]

 
(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.

    Table 3--Removal of Stage 1 HPT Airseal Ring, P/N 50L664, by CSN
------------------------------------------------------------------------
                                             Remove stage 1 HPT airseal
          For engine model . . .                    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 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, may approve AMOCs 
for this AD. Use the procedures found in 14 CFR 39.19 to make your 
request.

(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; email: [email protected].

(m) Material Incorporated by Reference

    None.

    Issued in Burlington, MA, on November 30, 2011.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-31177 Filed 12-5-11; 8:45 am]
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