Airworthiness Directives; Pratt & Whitney Division (PW) Turbofan Engines

[Federal Register Volume 83, Number 211 (Wednesday, October 31, 2018)]
[Rules and Regulations]
[Pages 54663-54665]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-23712]



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Federal Register / Vol. 83, No. 211 / Wednesday, October 31, 2018 / 
Rules and Regulations

[[Page 54663]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0368; Product Identifier 2018-NE-12-AD; Amendment 
39-19469; AD 2018-21-11]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Division (PW) Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: We are adopting a new airworthiness directive (AD) for all 
Pratt & Whitney Division (PW) PW4074D, PW4077D, PW4084D, PW4090, and 
PW4090-3 turbofan engines with a low-pressure compressor (LPC) fan hub, 
part number (P/N) 51B821 or P/N 52B521, installed. This AD was prompted 
by updated low-cycle fatigue analysis techniques that indicate certain 
LPC fan hubs could crack before their published life limit. This AD 
requires repetitive eddy current inspections (ECIs) and fluorescent 
penetrant inspections (FPIs) for cracks in certain LPC fan hubs and 
removal of LPC fan hubs from service that fail inspection. We are 
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective December 5, 2018.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of December 5, 
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 01803. 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-2018-0368.

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-2018-
0368; 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 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: 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 all PW PW4074D, PW4077D, 
PW4084D, PW4090, and PW4090-3 turbofan engines with an LPC fan hub, P/N 
51B821 or P/N 52B521, installed. The NPRM published in the Federal 
Register on July 19, 2018 (83 FR 34070). The NPRM was prompted by 
updated low-cycle fatigue analysis techniques that indicate certain LPC 
fan hubs could crack before their published life limit. The NPRM 
proposed to require repetitive ECIs and FPIs of the LPC fan hub. We are 
issuing this AD to address 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 Add Maximum Allowable Life

    The Air Line Pilots Association requested that we specify a maximum 
allowable life for the parts affected by this AD, in addition to the 
prescribed inspection interval, to ensure that the affected parts are 
not operated beyond a life limit in which it is likely that fatigue 
cracks will form.
    We disagree. This AD intends to specify a new inspection interval 
to reduce the risk of a fan hub failure due to potential low-cycle 
fatigue cracking. We determined that repetitive inspections, in 
conjunction with existing life limits for the small population of 
affected parts, maintains an acceptable level of safety for the fleet. 
The life limits for the affected parts are given in the appropriate 
Engine Manual, Chapter 5, Airworthiness Limitations Section. Operators 
are responsible for complying with those life limits. We did not change 
this AD.

Request To Clarify FPI Instructions

    All Nippon Airways requested clarification for performing the FPIs 
required by this AD. The instructions for performing ECIs are specified 
in PW Alert Service Bulletin (ASB) PW4G-112-A72-351, dated February 22, 
2018, which is incorporated by reference by this AD; however, 
instructions for performing FPIs are not specified.
    We disagree. FPI is an industry-standard inspection. Operators are 
permitted to use an FPI process that is equivalent to the FPI process 
conducted by the original equipment manufacturer. We are incorporating 
by reference the instructions for performing ECIs because ECI is not an 
industry standard practice. ECI requires procedures, tooling, 
acceptance, and rejection criteria that are specific to the part being 
inspected. We did not change this AD.

Request To Review Applicability

    PW stated that this AD should apply to all PW PW4074D, PW4077D, 
PW4084D, PW4090, and PW4090-3 turbofan engines with LPC fan hub, P/N 
51B821 or P/N 52B521, installed as of or after February 22, 2018.
    We disagree. The unsafe condition is present for any LPC fan hub, 
P/N 51B521 or P/N 52B521, installed in PW PW4074D, PW4077D, PW4084D, 
PW4090, and PW4090-3 turbofan engines regardless of the installation 
date. This AD requires inspections of all applicable LPC fan hubs, P/N 
51B521 or P/N 52B521, in service. We did not change this AD.

[[Page 54664]]

Clarification to Costs of Compliance

    We determined that we were not clear that only one LPC fan hub 
might need replacing. We clarified this in our cost estimate.

Support for the AD

    The Boeing Company expressed support for the NPRM as written.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this final rule as proposed except for minor editorial changes. We have 
determined that these minor changes:
    <bullet> Are consistent with the intent that was proposed in the 
NPRM for addressing the unsafe condition; and
    <bullet> Do not add any additional burden upon the public than was 
already proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

    We reviewed PW ASB PW4G-112-A72-351, dated February 22, 2018. The 
PW ASB describes procedures for performing LPC fan hub ECIs and 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 PW PW4000 Series 112 Inch Turbofan Engines Cleaning, 
Inspection and Repair (CIR) Manual, P/N 51A750, Chapter/Section 72-31-
07, Inspection/Check-02, Revision No. 77, dated July 15, 2018. The CIR 
Manual contains additional information regarding FPI and ECI of the LPC 
fan hub.

Costs of Compliance

    We estimate that this AD affects 32 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
----------------------------------------------------------------------------------------------------------------
Inspection............................  40 work-hours x $85 per               $0          $3,400        $108,800
                                         hour = $3,400.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary replacements 
that would be required based on the results of the proposed inspection. 
We estimate that one engine will need this replacement and estimate the 
parts cost using a prorated formula that takes the early removal of the 
life-limited part into account.

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace the LPC fan hub (prorated part cost)..  0 work-hours x $85 per hour = $0        $288,000        $288,000
----------------------------------------------------------------------------------------------------------------

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):

2018-21-11 Pratt & Whitney Division: Amendment 39-19469; Docket No. 
FAA-2018-0368; Product Identifier 2018-NE-12-AD.

[[Page 54665]]

(a) Effective Date

    This AD is effective December 5, 2018.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Pratt & Whitney Division (PW) PW4074D, 
PW4077D, PW4084D, PW4090, and PW4090-3 turbofan engines with low-
pressure compressor (LPC) fan hub, part number (P/N) 51B821 or P/N 
52B521, installed.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7230, Turbine Engine 
Compressor Section.

(e) Unsafe Condition

    This AD was prompted by low-cycle fatigue analysis techniques, 
updated by the engine manufacturer, which indicated certain LPC fan 
hubs could crack before their published life limit. We are issuing 
this AD to prevent failure of the LPC fan hub. The unsafe condition, 
if not addressed, could result in uncontained hub 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) After the effective date of this AD, perform a fluorescent 
penetrant inspection (FPI) and an eddy current inspection (ECI) of 
the LPC fan hub the next time the engine is separated at the M-
flange and the LPC fan hub has accumulated 2,000 or more flight 
cycles since the last FPI and ECI.
    (2) Thereafter, perform an FPI and an ECI of the LPC fan hub 
every time the engine is separated at the M-flange and the LPC fan 
hub has accumulated 2,000 or more flight cycles since the last LPC 
fan hub ECI and FPI.
    (3) Use the Accomplishment Instructions, Step No. 11, in PW 
Alert Service Bulletin PW4G-112-A72-351, dated February 22, 2018, to 
do the ECI.
    (4) If a crack is found during the inspections required by 
paragraphs (g)(1) or (2) of this AD, remove the LPC fan hub from 
service before further flight and replace with a part eligible for 
installation.

(h) 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 
certification office, send it to the attention of the person 
identified in paragraph (i) 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.

(i) Related Information

    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].

(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 Alert Service Bulletin PW4G-112-
A72-351, dated February 22, 2018.
    (ii) [Reserved.]
    (3) For 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 
01803. 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 October 25, 2018.
Robert J. Ganley,
Manager, Engine and Propeller Standards Branch, Aircraft Certification 
Service.
[FR Doc. 2018-23712 Filed 10-30-18; 8:45 am]
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