Airworthiness Directives; Pratt & Whitney Turbofan Engines

[Federal Register Volume 80, Number 205 (Friday, October 23, 2015)]
[Rules and Regulations]
[Pages 64312-64314]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-26346]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-0869; Directorate Identifier 2015-NE-11-AD; 
Amendment 39-18296; AD 2015-21-04]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
Pratt & Whitney (PW) PW4164, PW4168, PW4168A, PW4164-1D, PW4168-1D, 
PW4168A-1D, and PW4170 turbofan engines. This AD was prompted by crack 
finds in the 6th stage low-pressure turbine (LPT) disk. This AD 
requires

[[Page 64313]]

removal of the affected 6th stage LPT disks. We are issuing this AD to 
prevent failure of the 6th stage LPT disk, which could lead to an 
uncontained disk release, damage to the engine, and damage to the 
airplane.

DATES: This AD is effective November 27, 2015.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of November 27, 
2015.

ADDRESSES: 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 view this 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. It is also available on the Internet at 
http://www.regulations.gov by searching for and locating Docket No. 
FAA-2015-0869.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2015-
0869; 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: Besian Luga, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; phone: 781-238-7750; 
fax: 781-238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to all PW PW4164, PW4168, 
PW4168A, PW4164-1D, PW4168-1D, PW4168A-1D, and PW4170 turbofan engines. 
The NPRM published in the Federal Register on June 8, 2015 (80 FR 
32316). The NPRM was prompted by findings of cracks in the 6th stage 
LPT disk. The NPRM proposed to require removal of the affected 6th 
stage LPT disks. We are issuing this AD to correct the unsafe condition 
on these products.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comment received on the NPRM (80 FR 
32316, June 8, 2015) and the FAA's response to this comment.

Request to Clarify Definition of LPT Shop Visit

    An individual commenter requested that we define ``LPT shop visit'' 
more precisely to prevent unnecessary discussions regarding its 
meaning.
    We agree. We revised the definition to read: ``For the purpose of 
this AD, an ``LPT shop visit'' is defined as the removal of the 6th 
stage disk from the LPT rotor and the removal of the blades from the 
disk.''

Conclusion

    We reviewed the relevant data, considered the comment received, and 
determined that air safety and the public interest require adopting 
this AD with the change described previously.

Related Service Information Under 1 CFR Part 51

    We reviewed PW Service Bulletin (SB) No. PW4G-100-72-252, dated 
November 18, 2014. The SB provides a list of PW 6th stage LPT disks 
affected by this AD. This service information is reasonably available 
because the interested parties have access to it through their normal 
course of business or see ADDRESSES for other ways to access this 
service information.

Costs of Compliance

    We estimate that this AD affects 18 engines installed on airplanes 
of U.S. registry. We also estimate that no additional hours will be 
required per engine to comply with this AD because the engine is 
already disassembled in the shop when we require the part to be 
removed. The average labor rate is $85 per hour. We estimate that 6 
engines will require replacement parts during an LPT shop visit, and 
that the prorated replacement parts cost will be $108,800 per engine. 
Based on these figures, we estimate the cost of this AD on U.S. 
operators to be $652,800.

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

    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 to the extent 
that it justifies making a regulatory distinction, 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):

2015-21-04 Pratt & Whitney: Amendment 39-18296; Docket No. FAA-2015-
0869; Directorate Identifier 2015-NE-11-AD.

[[Page 64314]]

(a) Effective Date

    This AD is effective November 27, 2015.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Pratt & Whitney (PW) PW4164, PW4168, 
PW4168A, PW4164-1D, PW4168-1D, PW4168A-1D, and PW4170 turbofan 
engines with 6th stage low-pressure turbine (LPT) disks, part number 
50N886, installed.

(d) Unsafe Condition

    This AD was prompted by crack finds in the 6th stage LPT disk. 
We are issuing this AD to prevent failure of the 6th stage LPT disk, 
which could lead to an uncontained disk release, damage to the 
engine, and damage to the airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done. At the next LPT shop visit after the effective 
date of this AD, remove from service 6th stage LPT disks with serial 
numbers listed in the Accomplishment Instructions, Table 1, of PW 
Service Bulletin No. PW4G-100-72-252, dated November 18, 2014.

(f) Definition

    For the purpose of this AD, an ``LPT shop visit'' is defined as 
the removal of the 6th stage disk from the LPT rotor and the removal 
of the blades from the disk.

(g) 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. You may email your request to: [email protected].

(h) Related Information

    For more information about this AD, contact Besian Luga, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, MA 
01803; phone: 781-238-7750; fax: 781-238-7199; email: 
[email protected].

(i) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (3) The following service information was approved for IBR on 
November 27, 2015.
    (i) Pratt & Whitney (PW) Service Bulletin No. PW4G-100-72-252, 
dated November 18, 2014.
    (ii) Reserved.
    (4) For PW service information identified in this AD, contact 
Pratt & Whitney, 400 Main St., East Hartford, CT 06108; phone: 860-
565-8770; fax: 860-565-4503.
    (5) You may view this service information at 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.
    (6) You may view this service information at the National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call 202-741-6030, or go to: 
http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Burlington, Massachusetts, on October 9, 2015.
Robert G. Mann,
Acting Directorate Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2015-26346 Filed 10-22-15; 8:45 am]
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