[Federal Register Volume 85, Number 114 (Friday, June 12, 2020)]
[Proposed Rules]
[Pages 35812-35814]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-12626]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0542; Project Identifier AD-2020-00582-E]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Division Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all Pratt & Whitney Division (PW) PW4164, PW4164-1D, PW4168, 
PW4168-1D, PW4168A, PW4168A-1D, and PW4170 model turbofan engines with 
a certain outer combustion chamber assembly and 3rd stage low-pressure 
turbine (LPT) duct segments installed. This proposed AD was prompted by 
reports of damaged or failed 3rd stage LPT duct segments on PW engines 
with the Talon IIB outer combustion chamber assembly configuration 
installed. This proposed AD would require removing and replacing 
certain 3rd stage LPT duct segments. The FAA is proposing this AD to 
address the unsafe condition on these products.

[[Page 35813]]


DATES: The FAA must receive comments on this proposed AD by July 27, 
2020.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0542; 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 NPRM, any comments received, and other information. The street 
address for Docket Operations is listed above. Comments will be 
available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Carol Nguyen, Aerospace Engineer, ECO 
Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781-
238-7655; fax: 781-238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2020-0542; 
Project Identifier AD-2020-00582-E'' at the beginning of your comments. 
The FAA specifically invites comments on the overall regulatory, 
economic, environmental, and energy aspects of this NPRM. The FAA will 
consider all comments received by the closing date and may amend this 
NPRM because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
https://www.regulations.gov, including any personal information you 
provide. The FAA will also post a report summarizing each substantive 
verbal contact received about this NPRM.

Confidential Business Information

    Confidential Business Information (CBI) is commercial or financial 
information that is both customarily and actually treated as private by 
its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), 
CBI is exempt from public disclosure. If your comments responsive to 
this AD contain commercial or financial information that is customarily 
treated as private, that you actually treat as private, and that is 
relevant or responsive to this AD, it is important that you clearly 
designate the submitted comments as CBI. Please mark each page of your 
submission containing CBI as ``PROPIN.'' The FAA will treat such marked 
submissions as confidential under the FOIA, and they will not be placed 
in the public docket of this AD. Submissions containing CBI should be 
sent to Carol Nguyen, Aerospace Engineer, ECO Branch, FAA, 1200 
District Avenue, Burlington, MA, 01803. Any commentary that the FAA 
receives which is not specifically designated as CBI will be placed in 
the public docket for this rulemaking.

Discussion

    The FAA received multiple reports of damaged or failed 3rd stage 
LPT duct segments that resulted in engine surges, in-flight shutdowns, 
diversions, and air turnbacks. The reports were attributed to elevated 
gas path temperature at the outer diameter of the turbine flowpath and 
high-pressure turbine 2nd stage blade outer air seal spallation, which 
led to the distortion and liberation of 3rd stage LPT duct segments. 
This condition, if not addressed, could result in uncontained release 
of LPT blades and vanes, damage to the engine, and damage to the 
airplane.

Related Service Information

    The FAA reviewed PW Service Bulletin (SB) No. PW4G-100-72-214, 
dated December 15, 2011; PW SB No. PW4G-100-72-219, Revision 1, dated 
October 5, 2011; and PW SB No. PW4G-100-72-253, dated November 24, 
2014. PW SB No. PW4G-100-72-214 introduces the Talon IIB outer 
combustion chamber assembly that reduces the combustor exit temperature 
levels at the outer diameter of the combustor. PW SB No. PW4G-100-72-
219, Revision 1, describes procedures for installing the Advantage70 
engine upgrade kit to improve engine reliability and fuel consumption, 
and to reduce maintenance costs. PW SB No. PW4G-100-72-253 describes 
procedures for replacing the outer combustion chamber assembly waspaloy 
nuts.

FAA's Determination

    The FAA is proposing this AD because the Agency evaluated all the 
relevant information and determined the unsafe condition described 
previously is likely to exist or develop in other products of the same 
type design.

Proposed AD Requirements

    This proposed AD would require removing and replacing certain 3rd 
stage LPT duct segments.

Costs of Compliance

    The FAA estimates that this proposed AD affects 99 engines 
installed on airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this proposed 
AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                    Cost per       Cost on U.S.
               Action                        Labor cost           Parts cost        product         operators
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Remove and replace 3rd stage LPT      56 work-hours x $85 per         $85,000          $89,760       $8,886,240
 duct segments.                        hour = $4,760.
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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.
    The FAA is 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

[[Page 35814]]

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

    The FAA determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) 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.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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):

Pratt & Whitney Division: Docket No. FAA-2020-0542; Project 
Identifier AD-2020-00582-E.

(a) Comments Due Date

    The FAA must receive comments by July 27, 2020.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Pratt & Whitney Division (PW) PW4164, 
PW4164-1D, PW4168, PW4168-1D, PW4168A, PW4168A-1D, and PW4170 model 
turbofan engines that have 3rd stage low-pressure turbine (LPT) duct 
segments, part number (P/N) 50N434-01 or P/N 50N450-01 installed, 
and have the Talon IIB outer combustion chamber assembly, P/N 51J500 
or P/N 51J381, installed.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7250, Turbine 
Section.

(e) Unsafe Condition

    This AD was prompted by reports of damaged or failed 3rd stage 
LPT duct segments on PW engines with the Talon IIB outer combustion 
chamber assembly configuration installed. The FAA is issuing this AD 
to prevent failure of the 3rd stage LPT duct segments. The unsafe 
condition, if not addressed, could result in uncontained release of 
LPT blades and vanes, 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 Action

    At every engine shop visit after the effective date of this AD, 
remove from service the 3rd stage LPT duct segments, P/N 50N434-01 
and P/N 50N450-01, and replace them with parts with zero flight 
cycles.

(h) Terminating Action

    Removal of the 3rd stage LPT duct segments, P/N 50N434-01 and P/
N 50N450-01, and their replacement with parts having P/Ns other than 
P/N 50N434-01 and P/N 50N450-01, constitutes terminating action for 
the repetitive replacement required by paragraph (g) of this AD.

(i) Definition

    For the purpose of this AD, an ``engine shop visit'' is the 
induction of an engine into the shop for maintenance involving the 
separation of pairs of major mating engine flanges (lettered 
flanges). The separation of engine flanges solely for the purpose of 
transportation without subsequent engine maintenance does not 
constitute an engine shop visit.

(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 
certification office, send it to the attention of the person 
identified in paragraph (k) 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

    For more information about this AD, contact Carol Nguyen, 
Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: 781-238-7655; fax: 781-238-7199; email: 
[email protected].

    Issued on June 5, 2020.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2020-12626 Filed 6-11-20; 8:45 am]
 BILLING CODE 4910-13-P