[Federal Register Volume 83, Number 14 (Monday, January 22, 2018)]
[Rules and Regulations]
[Pages 2896-2899]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-00999]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0719; Product Identifier 2017-NE-22-AD; Amendment 
39-19163; AD 2018-02-10]
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) PW4074, PW4074D, PW4077, PW4077D, 
PW4084D, PW4090, and PW4090-3 turbofan engines. This AD was prompted by 
the discovery of multiple cracked outer diffuser cases. This AD 
requires initial and repetitive inspections to detect cracks in the 
outer diffuser case and removal from service of cases that fail 
inspection. We are issuing this AD to address the unsafe condition on 
these products.

DATES: This AD is effective February 26, 2018.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of February 26, 
2018.

ADDRESSES: For service information identified in this final rule, 
contact Pratt & Whitney Division, 400 Main St., East Hartford, CT 
06118; phone: 800-565-0140; fax: 860-565-5442. You may view this 
service information at the FAA, Engine and Propeller Standards Branch, 
1200 District Avenue, Burlington, MA. For information on the 
availability of this material at the FAA, call 781-238-7759. It is also 
available on the internet at http://www.regulations.gov by searching 
for and locating Docket No. FAA-2017-0719.

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-2017-
0719; or in person at Docket Operations between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays. The AD docket contains 
this final rule, the regulatory evaluation, any comments received, and 
other information. The address for Docket Operations (phone: 800-647-
5527) is Document Operations, U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor,

[[Page 2897]]

Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Jo-Ann Theriault, Aerospace Engineer, 
ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 
781-238-7105; fax: 781-238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to PW PW4074, PW4074D, PW4077, 
PW4077D, PW4084D, PW4090, and PW4090-3 turbofan engines. The NPRM 
published in the Federal Register on August 25, 2017 (82 FR 40514). The 
NPRM was prompted by the discovery of multiple cracked outer diffuser 
cases. The NPRM proposed to require initial and repetitive inspections 
to detect cracks in the outer diffuser case and removal from service of 
cases that fail inspection. We are issuing this AD to correct the 
unsafe condition on these products.

Comments

    We gave the public the opportunity to participate in developing 
this final rule. The following presents the comments received on the 
NPRM and the FAA's response to each comment.

Request To Change Compliance

    PW requested that we change the effective date of the 1,000 cycle 
drawdown to ``within 1,000 flight cycles from March 31, 2017'', to 
coincide with PW Alert Service Bulletin (ASB) PW4G-112-A72-347, rather 
than ``within 1,000 flight cycles from the effective date of this AD''. 
PW stated that making the 1,000 cycle drawdown effective March 31, 
2017, rather than the effective date of this AD, maintains the same 
level of risk.
    We disagree with changing the effective date of the 1,000 cycle 
drawdown to ``within 1,000 flight cycles from March 31, 2017'', to 
coincide with PW ASB PW4G-112-A72-347 because we cannot force mandatory 
action based on dates in the past. Mandatory action must be based on 
the effective date of this AD. In addition, we determined that basing 
the initial inspection and the inspection interval on the effective 
date of this AD maintains an acceptable level of safety. We did not 
change this AD.

Request To Add Credit for Previous Actions

    PW and United Airlines (UAL) requested that we add Credit for 
Previous Actions to allow operators to take credit for inspections 
performed per PW ASB PW4G-112-A72-347, dated March 31, 2017 prior to 
the effective date of this AD.
    We disagree. Since use of PW ASB PW4G-112-A72-347, dated March 31, 
2017, is required in the compliance section of this AD, we do not need 
to reference this SB in the Credit for Previous Actions paragraph. 
Inspections performed per PW ASB PW4G-112-A72-347 prior to the 
effective date of this AD meet the criteria of ``unless already done'' 
in the compliance section of this AD.

Request To Change Definitions

    UAL requested that we define ``engine disassembly'' as ``when the M 
flange is split''. UAL reasoned that this would clarify the compliance 
requirements for operators and is consistent with PW ASB PW4G-112-A72-
347, dated March 31, 2017.
    We agree. Defining ``engine disassembly'' clarifies compliance 
requirements for operators. We added a Definition paragraph to this AD.

Request To Change Compliance Time

    UAL requested that we add a third option for the initial inspection 
so that it could be performed prior to accumulating 13,000 cycles since 
new, or within 1,000 cycles from the effective date of this AD, or 
within 2,000 cycles since the last outer diffuser case piece-part 
fluorescent penetration inspection (FPI), whichever occurs later.
    We partially agree. We agree with giving operator's credit for 
inspections done at piece-part exposure because if the outer diffuser 
case was inspected at piece-part exposure and passed inspection, it 
meets the initial inspection requirement mandated by this AD. We added 
a ``Credit for Previous Actions'' paragraph to this AD. Therefore, we 
disagree with adding the third option to the initial inspection 
compliance time specified in paragraph (g)(1) of this AD.

Request To Change Compliance

    UAL requested that we identify the outer diffuser case piece-part 
level FPI done in accordance with PW Cleaning, Inspection and Repair 
(CIR) Manual 72-41-13, Inspection/Check-02, as an acceptable means of 
compliance for the repetitive inspections. UAL reasoned that when the 
outer diffuser case is at piece-part level, PW CIR Manual 72-41-13, 
Inspection/Check-02, is performed. The piece-part level FPI is 
equivalent to the high sensitivity module level inspection provided in 
PW ASB PW4G-112-A72-347, dated March 31, 2017.
    We agree. Inspections performed at piece-part exposure maintain an 
acceptable level of safety because the piece-part level FPI specified 
in PW CIR Manual Part Number 51A750, section 72-41-13, Inspection/
Check-02 is equivalent to the inspection mandated by this AD. Since we 
did not incorporate by reference a particular FPI process 
specification, a high sensitivity FPI using the methods, techniques, 
and practices equivalent to the current manufacturer's maintenance 
manual or Instructions for Continued Airworthiness satisfy both the 
initial and repetitive requirements of this AD. We did not change this 
AD.

Request To Change Service Information

    PW requested that we change the service information reference from 
PW ASB PW4G-112-A72-347, dated March 31, 2017, to PW ASB PW4G-112-A72-
347, Revision No. 1, dated October 26, 2017. PW stated that the SB has 
been revised to provide inspection clarifications requested by 
operators.
    We disagree. We did not include PW ASB PW4G-112-A72-347, Revision 
No. 1, dated October 26, 2017, since the risk analysis was based on the 
original ASB and we did not have the opportunity to give the public a 
chance to comment on this revision. We did not change this AD.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this final rule with the changes described previously. We have 
determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM for correcting the unsafe condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM.
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this final 
rule.

Related Service Information Under 1 CFR Part 51

    We reviewed PW ASB PW4G-112-A72-347, dated March 31, 2017. This PW 
ASB provides guidance on performing outer diffuser case FPIs. 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.

Other Related Service Information

    We reviewed PW4000 Series (112 Inch) Engine CIR Manual, Part Number 
51A750, Revision Number 74, section

[[Page 2898]]

72-41-13, Inspection/Check-02, dated July 15, 2017. This manual section 
provides guidance on performing a high sensitivity FPI of the outer 
diffuser case at piece-part exposure.

Costs of Compliance

    We estimate that this AD affects 121 engines installed on airplanes 
of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Tt3 boss inspection...................  3.5 work-hours x $85 per              $0         $297.50      $35,997.50
                                         hour = $297.50.
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    We estimate the following costs to do any necessary replacements 
that would be required based on the results of the proposed inspection. 
We estimate six cases will need to be replaced in the domestic fleet.

                                               On-Condition Costs
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                                                                                                     Cost per
                   Action                                 Labor cost                Parts cost        product
----------------------------------------------------------------------------------------------------------------
FPI Inspection of outer diffuser case......  10 work-hours x $85 per hour = $850              $0            $850
Replacement of outer diffuser case.........  $0.................................         750,000         750,000
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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.
    This AD is issued in accordance with authority delegated by the 
Executive Director, Aircraft Certification Service, as authorized by 
FAA Order 8000.51C. In accordance with that order, issuance of ADs is 
normally a function of the Compliance and Airworthiness Division, but 
during this transition period, the Executive Director has delegated the 
authority to issue ADs applicable to engines, propellers, and 
associated appliances to the Manager, Engine and Propeller Standards 
Branch, Policy and Innovation Division.

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, 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):

2018-02-10 Pratt & Whitney Division: Amendment 39-19163; Docket No. 
FAA-2017-0719; Product Identifier 2017-NE-22-AD.

(a) Effective Date

    This AD is effective February 26, 2018.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Pratt & Whitney Division (PW) PW4074, 
PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 turbofan 
engines with outer diffuser case, part number (P/N) 50J775 or P/N 
50J930, installed.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7240, Turbine Engine 
Combustion Section.

(e) Unsafe Condition

    This AD was prompted by the discovery of multiple cracked outer 
diffuser cases. We are issuing this AD to prevent failure of the 
outer diffuser case. The unsafe condition, if not corrected, could 
result in failure of the outer diffuser case, uncontained case 
release, damage to the engine, and damage to the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    (1) Perform an initial high sensitivity fluorescent penetrant 
inspection (FPI) of the outer diffuser case T3 thermocouple probe 
boss (Tt3 boss) prior to accumulating 13,000 cycles since new (CSN), 
or within 1,000 flight cycles from the effective date of this AD, 
whichever occurs later. If the case CSN is unknown, inspect within 
1,000 flight cycles from the effective date of this AD.

[[Page 2899]]

    (2) Thereafter, repeat the high sensitivity FPI of the outer 
diffuser case Tt3 boss within 2,000 flight cycles since the last 
FPI.
    (3) If an indication is found during the inspections required by 
paragraphs (g)(1) or (2) of this AD, re-inspect or remove the outer 
diffuser case from service as follows:
    (i) For engines installed on-wing, re-inspect or remove in 
accordance with the Accomplishment Instructions, Part A, paragraph 
1.G., of PW ASB PW4G-112-A72-347, dated March 31, 2017.
    (ii) For assembled engines not installed on-wing, re-inspect or 
remove in accordance with the Accomplishment Instructions, Part B, 
paragraph 1.C., of PW ASB PW4G-112-A72-347, dated March 31, 2017.
    (iii) For disassembled engines, if any cracks are found, remove 
the outer diffuser case from service before further flight.
    (4) Within 30 days of the effective date of this AD, update the 
mandatory inspections of the Airworthiness Limitations Section (ALS) 
of your Instructions for Continued Airworthiness to include the 
piece-part inspections of the diffuser case as defined in Figure 1 
to paragraph (g) of this AD.
[GRAPHIC] [TIFF OMITTED] TR22JA18.001

(h) Credit for Previous Actions

    You may take credit for the high sensitivity FPI of the outer 
diffuser case Tt3 boss that is required by paragraph (g)(1) of this 
AD if you performed a high sensitivity FPI of the outer diffuser 
case at piece-part exposure before the effective date of this AD, 
using PW4000 Series (112 Inch) Engine CIR Manual, P/N 51A750, 
section 72-41-13, Inspection/Check-02, dated July 15, 2017.

(i) Definition

    For the purpose of this AD, an engine is considered disassembled 
any time the ``M'' flange is separated.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, ECO Branch, FAA, has the authority to approve 
AMOCs for this AD, if requested using the procedures found in 14 CFR 
39.19. In accordance with 14 CFR 39.19, send your request to your 
principal inspector or local Flight Standards District Office, as 
appropriate. If sending information directly to the manager of the 
ECO Branch, send it to the attention of the person identified in 
paragraph (k)(1) of this AD. You may email your request to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(k) Related Information

    (1) For more information about this AD, contact Jo-Ann 
Theriault, Aerospace Engineer, ECO Branch, FAA, 1200 District 
Avenue, Burlington, MA 01803; phone: 781-238-7105; fax: 781-238-
7199; email: [email protected].
    (2) PW4000 Series (112 Inch) Engine CIR Manual, Part Number 
51A750, Revision Number 74, section 72-41-13, Inspection/Check-02, 
dated July 15, 2017, which is not incorporated by reference in this 
AD, can be obtained from PW, using the contact information in 
paragraph (l)(3) of this AD.

(l) 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 (PW) Alert Service Bulletin PW4G-112-A72-
347, dated March 31, 2017.
    (ii) Reserved.
    (3) For PW service information identified in this AD, contact 
Pratt & Whitney Division, 400 Main St., East Hartford, CT 06118; 
phone: 800-565-0140; fax: 860-565-5442.
    (4) You may view this service information at FAA, Engine and 
Propeller Standards Branch, 1200 District Avenue, Burlington, MA. 
For information on the availability of this material at the FAA, 
call 781-238-7759.
    (5) You may view this service information that is incorporated 
by reference 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 January 12, 2018.
Robert J. Ganley,
Manager, Engine and Propeller Standards Branch, Aircraft Certification 
Service.
[FR Doc. 2018-00999 Filed 1-19-18; 8:45 am]
 BILLING CODE 4910-13-P