Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

[Federal Register Volume 80, Number 118 (Friday, June 19, 2015)]
[Rules and Regulations]
[Pages 35191-35192]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-14992]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-0266; Directorate Identifier 2015-NE-03-AD; 
Amendment 39-18185; AD 2015-12-10]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Division Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for all 
Pratt & Whitney Division (PW) PW6122A and PW6124A turbofan engines. 
This AD requires initial and repetitive borescope inspections (BSIs) of 
the high-pressure compressor (HPC) 7th stage integrally bladed (IB) 
rotor aft integral arm for cracks until replacement of the HPC 7th 
stage IB rotor using non-silver-plated nuts. This AD was prompted by 
reports of crack finds in the HPC 7th stage IB rotor. We are issuing 
this AD to prevent HPC 7th stage IB rotor fractures, which could lead 
to uncontained engine failure and damage to the airplane.

DATES: This AD is effective July 6, 2015.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of July 6, 2015.
    We must receive comments on this AD by August 3, 2015.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
    <bullet> Fax: 202-493-2251.
    <bullet> 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.
    <bullet> Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    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-2015-0266.

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-
0266; 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 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: Wego Wang, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; phone: 781-238-7134; fax: 
781-238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    We received reports of cracks in the PW6122A and the PW6124A HPC 
7th stage IB rotor aft integral arm. The root cause is the presence of 
silver-plated nuts reacting with hot titanium in a high sulfur/high 
chlorine environment. This AD requires initial and repetitive BSIs of 
the HPC 7th stage IB rotor. This AD also requires, as terminating 
action, replacement of the HPC 7th stage IB rotor and HPC 7th stage IB 
rotor silver-plated nuts with non-silver-plated nuts. This condition, 
if not corrected, could result in HPC 7th stage IB rotor fractures. We 
are issuing this AD to prevent HPC 7th stage IB rotor fractures, which 
could lead to uncontained engine failure and damage to the airplane.

Related Service Information Under 1 CFR Part 51

    We reviewed PW Engineering Authorization (EA) No. 15MM008, Revision 
A, dated March 24, 2015. We also reviewed PW Service Bulletin (SB) No. 
PW6ENG 72-46, dated March 5, 2015. The EA describes procedures for BSIs 
of the HPC 7th stage IB rotor aft integral arm for cracks using the 
split-case method. The SB describes removal and replacement of the HPC 
7th stage IB rotor, removal of the HPC 7th stage IB rotor silver-plated 
nuts, and the installation of non-silver plated nuts. This service 
information is reasonably available because the interested parties have 
access to it through their normal course of business or by the means 
identified in the ADDRESSES section of this AD.

FAA's Determination

    We are issuing 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.

AD Requirements

    This AD requires initial and repetitive BSIs of the HPC 7th stage 
IB rotor. This AD also requires as terminating action to replace the 
HPC 7th stage IB rotor and HPC 7th stage IB rotor silver-plated nuts 
with non-silver-plated nuts.

FAA's Justification and Determination of the Effective Date

    No domestic operators use this product. Therefore, we find that 
notice and opportunity for prior public comment are unnecessary and 
that good cause exists for making this amendment effective in less than 
30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety and was not preceded by notice and an opportunity for public 
comment. However, we invite you to send any written data, views, or 
arguments about this AD. Send your comments to an address listed under 
the ADDRESSES section. Include ``Docket No. FAA-2015-0266; Directorate 
Identifier 2015-NE-03-AD'' at the beginning of your comments. We 
specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of this AD. We will consider all 
comments received by the closing date and may amend this 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 AD.

Costs of Compliance

    We estimate that this AD will affect 0 engines installed on 
airplanes of U.S. registry. We also estimate that it would take about 8 
hours per engine to comply with this AD. The average labor rate is $85 
per hour. Based on these figures, we

[[Page 35192]]

estimate the total cost of this AD to U.S. operators to be $0.

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):

2015-12-10 Pratt & Whitney Division: Amendment 39-18185; Docket No. 
FAA-2015-0266; Directorate Identifier 2015-NE-03-AD.

(a) Effective Date

    This AD is effective July 6, 2015.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Pratt & Whitney Division (PW) PW6122A and 
PW6124A turbofan engines with high-pressure compressor (HPC) 7th 
stage integrally bladed (IB) rotor, part number (P/N) 5495637, 
installed.

(d) Unsafe Condition

    This AD was prompted by reports of crack finds in the HPC 7th 
stage IB rotor. We are issuing this AD to prevent HPC 7th stage IB 
rotor fractures, which could lead to uncontained engine failure and 
damage to the airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.
    (1) Within 180 cycles after the effective date of this AD or 
within 6,500 cycles accumulated on the HPC 7th stage IB rotor, 
whichever occurs later, borescope inspect the HPC 7th stage IB rotor 
for cracks. Use Appendix 1, paragraphs 5 and 6 of PW Engineering 
Authorization 15MM008, Revision A, dated March 24, 2015, to do your 
inspection. Thereafter, repeat the inspection at every 1,000 cycles 
since last inspection.
    (2) If any crack is detected on the HPC 7th stage IB rotor, then 
before further flight, replace the HPC 7th stage IB rotor with a 
part eligible for installation.

(f) Mandatory Terminating Action

    (1) At the next shop visit after the effective date of this AD:
    (i) Replace the affected HPC 7th stage IB rotor, P/N 5495637, 
with a new, zero-time, HPC 7th stage IB rotor, P/N 5495637, and
    (ii) Remove the HPC 7th stage IB rotor silver-plated nuts, P/N 
4301682, and replace with non-silver-plated nuts. Use the 
Accomplishment Instructions of PW Service Bulletin No. PW6ENG 72-46, 
dated March 5, 2015 to perform the removal and replacement.

(g) Definition

    For the purposes of this AD an ``engine shop visit'' is the 
induction of an engine into the shop for maintenance involving the 
separation of pairs of major mating engine flanges. The separation 
of engine flanges solely for the purposes of transportation without 
subsequent engine maintenance, is not an engine shop visit.

(h) 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].

(i) Related Information

    For more information about this AD, contact Wego Wang, Aerospace 
Engineer, Engine Certification Office, FAA, Engine & Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803; 
phone: 781-238-7134; fax: 781-238-7199; email: [email protected].

(j) 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.
    (i) Pratt & Whitney Division (PW) Engineering Authorization No. 
15MM008, Revision A, dated March 24, 2015.
    (ii) PW Service Bulletin No. PW6ENG 72-46, dated March 5, 2015.
    (3) 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.
    (4) 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.
    (5) 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 June 9, 2015.
Ann C. Mollica,
Acting Directorate Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2015-14992 Filed 6-18-15; 8:45 am]
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