[Federal Register Volume 78, Number 156 (Tuesday, August 13, 2013)]
[Rules and Regulations]
[Pages 49111-49113]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-19429]
[[Page 49111]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2013-0072; Directorate Identifier 2013-NE-04-AD;
Amendment 39-17525; AD 2013-15-09]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney Division 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 all
Pratt & Whitney Division (PW) turbofan engine model PW4074, PW4074D,
PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 with a certain second-
stage high-pressure turbine (HPT) air seal part number installed. This
AD was prompted by discovery of cracks in second-stage HPT air seals.
This AD requires inspection and removal from service of HPT air seals
that fail inspection. We are issuing this AD to prevent failure of the
second-stage HPT air seal, which could lead to an uncontained engine
failure and damage to the airplane.
DATES: This AD is effective September 17, 2013. The Director of the
Federal Register approved the incorporation by reference of a certain
publication listed in the AD as of September 17, 2013.
ADDRESSES: The Docket Operations office is located at Docket Management
Facility, U.S. Department of Transportation, 1200 New Jersey Avenue
SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-
0001.
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.
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 street address for
the Docket Office (phone: 800-647-5527) is provided in the ADDRESSES
section. Comments will be available in the AD docket shortly after
receipt.
FOR FURTHER INFORMATION CONTACT: James Gray, Aerospace Engineer, Engine
& Propeller Directorate, FAA, 12 New England Executive Park,
Burlington, MA 01803; 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.
The NPRM published in the Federal Register on March 18, 2013 (78 FR
16620). The NPRM proposed to require, for those air seals that meet
certain cycles since new criteria, inspection and removal from service
of HPT air seals that fail inspection.
Comments
We gave the public the opportunity to participate in developing
this AD. The following presents the comments received on the proposal
(78 FR 16620, March 18, 2013) and the FAA's response to each comment.
Request To Provide Credit for Prior Compliance
All Nippon Airways Co., Ltd (ANA) and Japan Airlines (JAL)
requested that credit be provided for inspections that were performed
using prior versions of Alert Service Bulletin (ASB) No. PW4G-112-A72-
330. The reason for this request is that the inspection procedure and
inspection limits have not changed, so inspections using the prior
version of the ASB should remain valid.
We agree. We added a Credit for Previous Actions paragraph as
follows: ``You may take credit for eddy current inspections (ECIs)
performed prior to the effective date of this AD using PW ASB No. PW4G-
112-A72-330, dated December 3, 2012 or PW ASB No. PW4G-112-A72-330,
Revision 1, dated February 26, 2013.''
Request To Change Compliance Time
ANA, JAL, PW, and United Airlines (UAL) requested that the
Compliance paragraph for the on-wing ECI be changed to remove the air
seal from service within five cycles, instead of before further flight.
The inspection will likely be performed on-wing and not at a major
maintenance facility. Removal from service before further flight would
lead to potential aircraft-on-ground situations. The change is also
consistent with the PW ASB.
We agree. Removal from service within five cycles maintains an
acceptable level of safety while allowing the operators some
flexibility in removing the part from service. We changed the
Compliance paragraph of this AD to fulfill this request.
Request for Clarification of Terminating Action
ANA requested clarification on what the terminating action is.
Although not specifically stated, the inferrence is that the commenter
wants terminating action to be included in the AD.
We partially agree. We agree that the inspection program is an
interim action. The terminating action to the repetitive inspections
will be installation of a redesigned second-stage HPT air seal. We
disagree with revising the AD to include terminating action at this
time because the redesign is not yet available. We will take
appropriate actions when the redesign is available. We did not change
the AD.
Request To Delay Issuance of AD
UAL requested that the AD be delayed for six months and that the
comment period be re-opened. The reason for this request is that the
majority of operators have not received training or have just received
training on the inspection procedure and therefore are unable to
provide substantive comments. Delaying the comment period will allow
for more substantive comments to the NPRM (78 FR 16620, March 18,
2013).
We do not agree. The risk analysis does not support delaying the AD
an additional six months. It is anticipated that all operators will
receive training prior to the AD becoming effective. If changes to the
inspection procedure are required, they can be handled through the
Alternative Methods of Compliance paragraph of this AD. We did not
change the AD.
Request To Not Mandate Use of the Service Bulletin Incorporated By
Reference (IBR)
UAL and PW requested that the AD not mandate the service bulletin
IBR and include just the inspection criteria in the AD, or modify the
mandated actions to only include the inspection criteria. The reason
for this request is that the inspection procedure needs to be flexible
and adaptable as unexpected inspection procedures are found. One
commenter also identified several issues with the way the inspection
procedure is currently worded, including use of a ``50 foot extension
cord'' and a ``black Sharpie'' which, if included in the IBR, would
force operators to use these specific items.
We partially agree. We agree that the the AD does not need to
mandate the
[[Page 49112]]
entire inspection procedure, because not all aspects of the inspection
procedure are unique. We disagree with not mandating the service
bulletin at all, because aspects of the ECI are unique and would not
necessarily be covered under general maintenance. If performed
incorrectly, the inspection might not detect potential cracks. We
revised this AD to only mandate the inspection itself, including how to
disposition the ECI results.
Request To Address Serviceability Limits
UAL noted that ASB No. PW4G-112-A72-330, Revision 1, dated February
26, 2013, allows for some grinding of the T-2 nozzle guide vane (NGV),
if needed, to gain access to the second-stage HPT airseal. There is
also a procedure in the ASB to use an alternate access port if there is
entrapped material preventing access to the primary port. The commenter
requested that serviceability limits for both of these scenarios be
included in the ASB. There was no justification provided for this
request. It is inferred that the commenter is concerned that
serviceability limits were not included.
We do not agree. Grinding of the T-2 NGV and using the alternate
access port are not necessarily required to perform the inspection and
are not mandated as part of this AD. We did not change the AD.
Request To Include Reduced Inspection Interval
UAL requested that we include a reduced inspection interval based
on the results of the ECI, as described in PW ASB No. PW4G-112-A72-330.
The change is requested because this interval is included in the ASB,
but not included in the NPRM (78 FR 16620, March 18, 2013).
We agree. The reduced inspection interval was unintentionally
omitted in the NPRM (78 FR 16620, March 18, 2013). We revised the AD as
requested.
Request To Change Compliance Time
PW requested that the 1,000 cycle drawdown in paragraph (e)(2) of
the NPRM (78 FR 16620, March 18, 2013) be effective December 2012, as
opposed to after the effective date of the AD, to coincide with PW ASB
No. PW4G-112-A72-330.
We do not agree. We cannot reference a date in the past, as
requested, since operators must have the opportunity to comply with the
AD. We did not change the AD.
Conclusion
We reviewed the relevant data, considered the comments received,
and determined that air safety and the public interest require adopting
this AD with the changes described previously and minor editorial
changes. We have determined that these minor changes:
Are consistent with the intent that was proposed in the
NPRM (78 FR 16620, March 18, 2013) for correcting the unsafe condition;
and
Do not add any additional burden upon the public than was
already proposed in the NPRM (78 FR 16620, March 18, 2013).
We also determined that these changes will not increase the
economic burden on any operator or increase the scope of this AD.
Interim Action
We consider this AD interim action. PW has not determined the root
cause of the cracks discovered in second-stage HPT air seals.
Costs of Compliance
We estimate that this AD will affect 83 engines installed on
airplanes of U.S. registry. We also estimate that it will take about 5
hours to perform the inspection required by this AD. The costs of an
on-wing ECI or in-shop fluorescent-penetrant inspection (FPI) are
assumed to be equal. The average labor rate is $85 per hour. Based on
these figures, we estimate the total cost of the AD to U.S. operators
will be $35,275.
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):
2013-15-09 Pratt & Whitney Division: Amendment 39-17525; Docket No.
FAA-2013-0072; Directorate Identifier 2013-NE-04-AD.
(a) Effective Date
This AD is effective September 17, 2013.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all Pratt & Whitney Division (PW) turbofan
engine models PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and
PW4090-3 with second-stage high-pressure turbine (HPT) air seal,
part number 54L041, installed.
(d) Unsafe Condition
This AD was prompted by discovery of cracks in second-stage HPT
air seals. We are issuing this AD to prevent failure of the second-
stage HPT air seal, which could lead to uncontained engine failure
and damage to the airplane.
[[Page 49113]]
(e) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(1) For second-stage HPT air seals that have 1,200 or fewer
cycles since new (CSN) on the effective date of this AD, perform an
initial on-wing eddy current inspection (ECI) or initial in-shop
fluorescent-penetrant inspection (FPI) for cracks within 2,200 CSN.
(2) For second-stage HPT air seals that have more than 1,200 CSN
on the effective date of this AD, perform an initial on-wing ECI or
initial in-shop FPI for cracks within 1,000 cycles after the
effective date of this AD.
(3) Thereafter, repeat either the on-wing ECI or in-shop FPI
every 1,200 cycles or fewer, since last inspection, depending on the
results of the inspection.
(4) For the on-wing ECI, use section 4.0 of the Appendix of PW
Alert Service Bulletin (ASB) No. PW4G-112-A72-330, Revision 2, dated
July 11, 2013, to perform the inspection and use paragraph 8 of the
Accomplishment Instructions of PW ASB No. PW4G-112-A72-330, Revision
2, dated July 11, 2013, to disposition the results of the
inspection.
(5) For the in-shop FPI, remove the air seal from service if you
find a crack.
(f) Credit for Previous Actions
You may take credit for ECIs performed prior to the effective
date of this AD using PW ASB No. PW4G-112-A72-330, dated December 3,
2012 or PW ASB No. PW4G-112-A72-330, Revision 1, dated February 26,
2013.
(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.
(h) Related Information
For more information about this AD, contact James Gray,
Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New
England Executive Park, Burlington, MA 01803; phone: 781-238-7742;
fax: 781-238-7199; email: [email protected].
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 Alert Service Bulletin No. PW4G-112-A72-330,
Revision 2, dated July 11, 2013.
(ii) Reserved.
(3) 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.
(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 July 19, 2013.
Colleen M. D'Alessandro,
Assistant Manager, Engine & Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 2013-19429 Filed 8-12-13; 8:45 am]
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