AD 2015-12-10
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney Division | PW6122A | Airworthiness Directives; Pratt & Whitney Division Turbofan Engines |
| engine | Pratt & Whitney Division | PW6124A | Airworthiness Directives; Pratt & Whitney Division Turbofan Engines |
Unsafe Condition
Reports of cracks in the high-pressure compressor (HPC) 7th stage integrally bladed (IB) rotor aft integral arm, which could lead to rotor fractures and uncontained engine failure.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Initial and repetitive borescope inspections (BSIs) of the HPC 7th stage IB rotor for cracks. Replace the HPC 7th stage IB rotor if cracks are detected. At the next shop visit, replace the HPC 7th stage IB rotor and remove silver-plated nuts, replacing them with non-silver-plated nuts.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 180 cycles after the effective date or within 6,500 cycles accumulated on the HPC 7th stage IB rotor, whichever occurs later. Repetitive inspections every 1,000 cycles thereafter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
All Pratt & Whitney Division PW6122A and PW6124A turbofan engines with HPC 7th stage IB rotor, part number 5495637.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
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.
Applicability Source Text
Show captured applicability text from the source AD
(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.
Document Text
Show stored source text (verify against official source)
[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 [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2015-14992]
=======================================================================
-----------------------------------------------------------------------
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.
-----------------------------------------------------------------------
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 <a href="http://www.regulations.gov">http://www.regulations.gov</a>. 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
<a href="http://www.regulations.gov">http://www.regulations.gov</a> by searching for and locating Docket No.
FAA-2015-0266.
Examining the AD Docket
You may examine the AD docket on the Internet at <a href="http://www.regulations.gov">http://www.regulations.gov</a> 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: <a href="/cdn-cgi/l/email-protection#a3d4c6c4cc8dd4c2cdc4e3c5c2c28dc4ccd5"><span class="__cf_email__" data-cfemail="aed9cbc9c180d9cfc0c9eec8cfcf80c9c1d8">[email protected]</span></a>.
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 <a href="http://www.regulations.gov">http://www.regulations.gov</a>, 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: <a href="/cdn-cgi/l/email-protection#1c5d5259315d58315d51535f5c7a7d7d327b736a"><span class="__cf_email__" data-cfemail="15545b503854513854585a56557374743b727a63">[email protected]</span></a>.
(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: <a href="/cdn-cgi/l/email-protection#d4a3b1b3bbfaa3b5bab394b2b5b5fab3bba2"><span class="__cf_email__" data-cfemail="334456545c1d44525d54735552521d545c45">[email protected]</span></a>.
(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:
<a href="http://www.archives.gov/federal-register/cfr/ibr-locations.html">http://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.
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]
BILLING CODE 4910-13-P
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.