Document ID: FAA-2013-0072-0009
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Pratt and Whitney Division Turbofan Engines
Posted Date: 2013-08-13T04:00Z

[Federal Register Volume 78, Number 156 (Tuesday, August 13, 2013)]
[Rules and Regulations]
[Pages 49111-49113]
From the Federal Register Online via the Government Printing 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: 
james.e.gray@faa.gov.

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: james.e.gray@faa.gov.

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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