AD 2014-17-08R1
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney Canada Corp. | PT6A-114 | Airworthiness Directives; Pratt & Whitney Canada Corp. Turboprop Engines |
| engine | Pratt & Whitney Canada Corp. | PT6A-114A | Airworthiness Directives; Pratt & Whitney Canada Corp. Turboprop Engines |
Unsafe Condition
Failure of compressor turbine (CT) blades could result in damage to the engine and damage to the airplane.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Conduct initial and repetitive borescope inspections (BSIs) of CT blades and remove from service blades that fail inspection. Install an additional single crystal CT blade to correct the unsafe condition.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Effective June 5, 2015.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Pratt & Whitney Canada Corp. PT6A-114 and PT6A-114A turboprop engines.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Compressor turbine (CT) blades
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - 2014-17-08R1.pdf
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DetailsAttachments/Public Comments
AD Number:
2014-17-08R1
Document Type:
AD Final Rules
Docket Number:
FAA-2013-0766
Subject Heading:
Airworthiness Directives; Pratt & Whitney Canada Corp. Turboprop Engines
Subject:
Compressor turbine (CT) blades
Status:
Current
Citation:
Federal Register Volume 80, Number 84 (Friday, May 1, 2015)
Citation Publish Date:
05/01/2015
Effective Date:
06/05/2015
Make:
Pratt & Whitney Canada Corp.
Model:
PT6A-114 | PT6A-114A
Product Type:
Engine
Product Subtype:
Affected AD:
Superseded AD:
2014-17-08
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
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[Federal Register Volume 80, Number 84 (Friday, May 1, 2015)]
[Rules and Regulations]
[Pages 24791-24793]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-10075]
––––––––––––––––––––––––––––––––––
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2013-0766; Directorate Identifier 2013-NE-26-AD; Amendment 39-18149;
AD 2014-17-08R1]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney Canada Corp. Turboprop Engines
AGENCY:
Federal Aviation Administration (FAA), DOT.
ACTION:
Final rule.
––––––––––––––––––––––––––––––––––
SUMMARY:
We are revising airworthiness directive (AD) 2014-17-08 for all Pratt & Whitney
Canada Corp. (P&WC) PT6A-114 and PT6A-114A turboprop engines. AD 2014-17-08 required
initial and repetitive borescope inspections (BSIs) of compressor turbine (CT) blades, and the
removal from service of blades that fail inspection. This new AD adds an additional single crystal CT
blade, reduces the affected population, and corrects the Credit for Previous Action paragraph. This
AD was prompted by P&WC development of an additional single crystal CT blade that corrects the
unsafe condition. We are issuing this AD to prevent failure of CT blades, which could result in
damage to the engine and damage to the airplane.
DATES:
This AD is effective June 5, 2015.
The Director of the Federal Register approved the incorporation by reference of a certain other
publications listed in this AD as of October 8, 2014 (79 FR 52172, September 3, 2014).
ADDRESSES:
For service information identified in this AD, contact Pratt & Whitney Canada Corp.,
1000 Marie-Victorin, Longueuil, Quebec, Canada, J4G 1A1; phone: 800-268-8000; fax: 450-647-
2888; Internet: www.pwc.ca. 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. Certain service information is also available on the
Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2013-0766.
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-2013-0766; 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,
2
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:
Barbara Caufield, Aerospace Engineer, Engine
Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park,
Burlington, MA 01803; phone: 781-238-7146; fax: 781-238-7199; email: barbara.caufield@faa.gov.
SUPPLEMENTARY INFORMATION:
Discussion
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to revise AD
2014-17-08, Amendment 39-17961 (79 FR 52172, September 3, 2014), (''AD 2014-17-08''). AD
2014-17-08 applied to all P&WC PT6A-114 and PT6A-114A turboprop engines. The NPRM
published in the Federal Register on December 1, 2014 (79 FR 71031). The NPRM was prompted by
P&WC development of an additional single crystal CT blade that corrects the unsafe condition. The
addition of this new part number (P/N) reduces the affected population. The NPRM proposed to
retain all the requirements of AD 2014-17-08. The NPRM also proposed to add the additional single
crystal CT blade that corrects the unsafe condition, reduce the affected population, and correct the
Credit for Previous Action paragraph. We are issuing this AD to prevent failure of CT blades, which
could result in damage to the engine and damage to the airplane.
Comments
We gave the public the opportunity to participate in developing this AD. The following presents
the comments received on the NPRM (79 FR 71031, December 1, 2014) and the FAA's response to
each comment.
Request To Clarify Disposition of Removed CT Blades
Hawkins Aero Engineering, Inc. and another commenter requested that we state more clearly
whether pre-SB (service bulletin) PT6A-72-1669 CT blades removed as a result of this AD can be
reinstalled in the same engine, the same model engine, or a different model engine.
We disagree. Paragraph (e)(1)(iii)(B) of this AD clearly states that to re-install removed pre-SB
PT6A-72-1669 CT blades, the blades must pass a two-blade metallurgical inspection to determine
airworthiness in accordance with paragraph 3.B., Accomplishment Instructions, of P&WC Service
Bulletin (SB) No. PT6A-72-1669, Revision 9, dated June 28, 2013. We did not change this AD.
Request To Not Mandate Installation of Single Crystal CT Blades
One commenter requested that we not mandate the installation of single crystal CT blades
because two of the P/Ns cited as replacement blades have experienced low-time failures, indicating a
design or manufacturing flaw.
We disagree. While there have been some failures of single crystal CT blades on a different
engine model, that failure mode is well understood and does not affect the engines that are the subject
of this AD. For the engines that are subject to this AD, single crystal blades provide a significant
improvement in durability and a significant reduction in CT blade failures overall. We did not change
this AD.
Document Text
Show stored source text (verify against official source)
AD Final Rules - 2014-17-08R1.pdf
Copy URL
Document Versions
Feedback
DetailsAttachments/Public Comments
AD Number:
2014-17-08R1
Document Type:
AD Final Rules
Docket Number:
FAA-2013-0766
Subject Heading:
Airworthiness Directives; Pratt & Whitney Canada Corp. Turboprop Engines
Subject:
Compressor turbine (CT) blades
Status:
Current
Citation:
Federal Register Volume 80, Number 84 (Friday, May 1, 2015)
Citation Publish Date:
05/01/2015
Effective Date:
06/05/2015
Make:
Pratt & Whitney Canada Corp.
Model:
PT6A-114 | PT6A-114A
Product Type:
Engine
Product Subtype:
Affected AD:
Superseded AD:
2014-17-08
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
Automatic Zoom
Actual Size
Page Fit
Page Width
50%
75%
100%
125%
150%
200%
300%
400%
125%
of 7
1
[Federal Register Volume 80, Number 84 (Friday, May 1, 2015)]
[Rules and Regulations]
[Pages 24791-24793]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-10075]
––––––––––––––––––––––––––––––––––
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2013-0766; Directorate Identifier 2013-NE-26-AD; Amendment 39-18149;
AD 2014-17-08R1]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney Canada Corp. Turboprop Engines
AGENCY:
Federal Aviation Administration (FAA), DOT.
ACTION:
Final rule.
––––––––––––––––––––––––––––––––––
SUMMARY:
We are revising airworthiness directive (AD) 2014-17-08 for all Pratt & Whitney
Canada Corp. (P&WC) PT6A-114 and PT6A-114A turboprop engines. AD 2014-17-08 required
initial and repetitive borescope inspections (BSIs) of compressor turbine (CT) blades, and the
removal from service of blades that fail inspection. This new AD adds an additional single crystal CT
blade, reduces the affected population, and corrects the Credit for Previous Action paragraph. This
AD was prompted by P&WC development of an additional single crystal CT blade that corrects the
unsafe condition. We are issuing this AD to prevent failure of CT blades, which could result in
damage to the engine and damage to the airplane.
DATES:
This AD is effective June 5, 2015.
The Director of the Federal Register approved the incorporation by reference of a certain other
publications listed in this AD as of October 8, 2014 (79 FR 52172, September 3, 2014).
ADDRESSES:
For service information identified in this AD, contact Pratt & Whitney Canada Corp.,
1000 Marie-Victorin, Longueuil, Quebec, Canada, J4G 1A1; phone: 800-268-8000; fax: 450-647-
2888; Internet: www.pwc.ca. 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. Certain service information is also available on the
Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2013-0766.
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-2013-0766; 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,
2
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:
Barbara Caufield, Aerospace Engineer, Engine
Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park,
Burlington, MA 01803; phone: 781-238-7146; fax: 781-238-7199; email: barbara.caufield@faa.gov.
SUPPLEMENTARY INFORMATION:
Discussion
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to revise AD
2014-17-08, Amendment 39-17961 (79 FR 52172, September 3, 2014), (''AD 2014-17-08''). AD
2014-17-08 applied to all P&WC PT6A-114 and PT6A-114A turboprop engines. The NPRM
published in the Federal Register on December 1, 2014 (79 FR 71031). The NPRM was prompted by
P&WC development of an additional single crystal CT blade that corrects the unsafe condition. The
addition of this new part number (P/N) reduces the affected population. The NPRM proposed to
retain all the requirements of AD 2014-17-08. The NPRM also proposed to add the additional single
crystal CT blade that corrects the unsafe condition, reduce the affected population, and correct the
Credit for Previous Action paragraph. We are issuing this AD to prevent failure of CT blades, which
could result in damage to the engine and damage to the airplane.
Comments
We gave the public the opportunity to participate in developing this AD. The following presents
the comments received on the NPRM (79 FR 71031, December 1, 2014) and the FAA's response to
each comment.
Request To Clarify Disposition of Removed CT Blades
Hawkins Aero Engineering, Inc. and another commenter requested that we state more clearly
whether pre-SB (service bulletin) PT6A-72-1669 CT blades removed as a result of this AD can be
reinstalled in the same engine, the same model engine, or a different model engine.
We disagree. Paragraph (e)(1)(iii)(B) of this AD clearly states that to re-install removed pre-SB
PT6A-72-1669 CT blades, the blades must pass a two-blade metallurgical inspection to determine
airworthiness in accordance with paragraph 3.B., Accomplishment Instructions, of P&WC Service
Bulletin (SB) No. PT6A-72-1669, Revision 9, dated June 28, 2013. We did not change this AD.
Request To Not Mandate Installation of Single Crystal CT Blades
One commenter requested that we not mandate the installation of single crystal CT blades
because two of the P/Ns cited as replacement blades have experienced low-time failures, indicating a
design or manufacturing flaw.
We disagree. While there have been some failures of single crystal CT blades on a different
engine model, that failure mode is well understood and does not affect the engines that are the subject
of this AD. For the engines that are subject to this AD, single crystal blades provide a significant
improvement in durability and a significant reduction in CT blade failures overall. We did not change
this AD.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.
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