Document ID: FAA-2022-0384-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Pratt and Whitney Turbofan Engines
Posted Date: 2022-04-04T04:00Z

[Federal Register Volume 87, Number 64 (Monday, April 4, 2022)]
[Proposed Rules]
[Pages 19405-19409]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-07013]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0384; Project Identifier AD-2022-00027-E]
RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD) 
2021-14-06, which applies to all Pratt & Whitney (PW) PW1519G, PW1521G, 
PW1521G-3, PW1521GA, PW1524G, PW1524G-3, PW1525G, PW1525G-3, PW1919G, 
PW1921G, PW1922G, PW1923G, and PW1923G-A model turbofan engines. AD 
2021-14-06 requires repetitive borescope inspections (BSI) of certain 
low-pressure compressor (LPC) rotor 1 (R1) until replacement of 
electronic engine control (EEC) full authority digital electronic 
control (FADEC) software with updated software. AD 2021-14-06 also 
requires a BSI after installation of the updated EEC FADEC software if 
certain Onboard Maintenance Message fault codes are displayed and meet 
specified criteria. AD 2021-14-06 also requires, depending on the 
results of the BSI, replacement of the LPC R1. Since the FAA issued AD 
2021-14-06, the manufacturer redesigned the compressor intermediate 
case (CIC) assembly to incorporate a shortened bleed duct configuration 
and updated the EEC FADEC software. This proposed AD would continue to 
require repetitive BSI of certain LPC R1s until replacement of EEC 
FADEC software with updated software and also a BSI after installation 
of the updated EEC FADEC software if certain Onboard Maintenance 
Message fault codes are displayed and meet specified criteria. This 
proposed AD would continue to require, depending on the results of the 
BSI, replacement of the LPC R1. This proposed AD would also require 
removal and replacement of the existing CIC assembly with a CIC 
assembly eligible for installation. The FAA is

[[Page 19406]]

proposing this AD to address the unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by May 19, 
2022.

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.
    For service information identified in this NPRM, contact Pratt & 
Whitney, 400 Main Street, East Hartford, CT 06118; phone: (800) 565-
0140; email: [email protected]; website: http://fleetcare.pw.utc.com. 
You may view this service information at the Airworthiness Products 
Section, FAA, 1200 District Avenue, Burlington, MA 01803. For 
information on the availability of this material at the FAA, call (817) 
222-5110.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2022-0384; 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.

FOR FURTHER INFORMATION CONTACT: Mark Taylor, Aviation Safety Engineer, 
ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 
(781) 238-7229; 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 ADDRESSES. Include ``Docket No. FAA-2022-0384; Project Identifier 
AD-2022-00027-E'' at the beginning of your comments. The most helpful 
comments reference a specific portion of the proposal, explain the 
reason for any recommended change, and include supporting data. The FAA 
will consider all comments received by the closing date and may amend 
the proposal 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 agency will also post a report summarizing each 
substantive verbal contact we receive about this proposed AD.

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 NPRM 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 NPRM, 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 NPRM. Submissions containing CBI should be sent to Mark 
Taylor, Aviation Safety 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.

Background

    The FAA issued AD 2021-14-06, Amendment 39-21633 (86 FR 36061, July 
8, 2021), (AD 2021-14-06), for all PW PW1519G, PW1521G, PW1521G-3, 
PW1521GA, PW1524G, PW1524G-3, PW1525G, PW1525G-3, PW1919G, PW1921G, 
PW1922G, PW1923G, and PW1923G-A model turbofan engines. AD 2021-14-06 
was prompted by reports of in-flight shutdowns due to failure of the 
LPC R1 and by subsequent findings of cracked LPC R1s during inspection. 
Additionally, the manufacturer performed further root cause analysis of 
the LPC R1 failures and determined the need to update the EEC FADEC 
software to automate rotor speed management and limit the maximum climb 
and maximum continuous thrust ratings. AD 2021-14-06 requires 
repetitive BSIs of certain LPC R1s until replacement of EEC FADEC 
software with the updated software, and a BSI after installation of the 
updated EEC FADEC software if certain Onboard Maintenance Message fault 
codes are displayed and meet specified criteria. AD 2021-14-06 also 
requires, depending on the results of the BSI, replacement of the LPC 
R1. The agency issued AD 2021-14-06 to prevent failure of the LPC R1.

Actions Since AD 2021-14-06 Was Issued

    Since the FAA issued AD 2021-14-06, the manufacturer performed 
further analysis and determined the need for corrective action. The 
manufacturer redesigned the CIC assembly to incorporate a shortened 
bleed duct configuration. The shortened bleed duct will address the 
unsafe condition by preventing the coincidence between bleed and the 
acoustic excitation. The manufacturer also updated the EEC FADEC 
software to provide compatibility with both current and future 
operation of engines and airplanes with the redesigned CIC assembly 
installed.

FAA's Determination

    The FAA is issuing this NPRM after determining that the unsafe 
condition described previously is likely to exist or develop on other 
products of the same type design.

Related Service Information

    The FAA reviewed PW Service Bulletin (SB) PW1000G-A-73-00-0025-00B-
930A-D, Issue No. 001, dated November 23, 2021; PW SB PW1000G-A-72-00-
0125-00A-930A-D, Issue No. 004, dated October 13, 2021; PW SB PW1000G-
A-72-00-0075-00B-930A-D, Issue No. 004, dated July 21, 2021; PW SB 
PW1000G-A-73-00-0052-00A-930A-D, Issue No. 001, dated October 7, 2021; 
PW SB PW1000G-A-72-00-0121-00B-930A-D, Issue No. 001, dated July 9, 
2021; PW SB PW1000G-A-72-00-0175-00A-930A-D, Issue No. 001, dated July 
1, 2021.
    PW SB PW1000G-A-73-00-0025-00B-930A-D, Issue No. 001, dated 
November 23, 2021, describes procedures for replacing or modifying the 
EEC to incorporate EEC FADEC software version V9.6.5.6 in PW1919G, 
PW1921G, PW1922G, PW1923G, and PW1923G-A model turbofan engines. PW SBs 
PW1000G-A-72-00-0125-00A-930A-D, Issue No. 004, dated October 13, 2021, 
and PW1000G-A-72-00-0075-00B-930A-D, Issue No. 004, dated July 21, 
2021, describe procedures for performing repetitive BSIs of LPC R1s. PW 
SB PW1000G-A-73-00-0052-00A-930A-D, Issue No. 001, dated October 7, 
2021, describes procedures for replacing or modifying the EEC to

[[Page 19407]]

incorporate EEC FADEC software version V2.11.12 in PW1519G, PW1521G, 
PW1521G-3, PW1521GA, PW1524G, PW1524G-3, PW1525G, PW1525G-3 model 
turbofan engines. PW SBs PW1000G-A-72-00-0121-00B-930A-D, Issue No. 
001, dated July 9, 2021, and PW1000G-A-72-00-0175-00A-930A-D, Issue No. 
001, dated July 1, 2021, describe procedures for replacing or modifying 
the CIC assembly.
    The FAA also reviewed Section PW1000G-A-72-00-00-02A-0B5A-A of PW 
engine maintenance manual (EMM), Issue No. 016, dated January 15, 2021; 
and Section PW1000G-A-72-31-00-00A-312A-D of PW EMM, Issue No. 017, 
dated March 19, 2021. Section PW1000G-A-72-00-00-02A-0B5A-A of PW EMM, 
Issue No. 016, dated January 15, 2021, describes procedures for 
inspecting the engine for possible engine damage after receiving 
notification of an N1 or N2 overspeed operation. Section PW1000G-A-72-
31-00-00A-312A-D of PW EMM, Issue No. 017, dated March 19, 2021, 
describes procedures for performing a BSI of the LPC.

Proposed AD Requirements in This NPRM

    This proposed AD would retain certain requirements of AD 2021-14-
06. This proposed AD would continue to require removal from service of 
certain EEC FADEC software and the installation of a software version 
eligible for installation. This proposed AD would require a BSI of LPC 
R1 for damage and cracks after replacing certain EEC FADEC software 
versions and would continue to require a BSI of LPC R1 after 
installation of an eligible EEC FADEC software version if certain 
Onboard Maintenance Message fault codes are displayed and meet 
specified criteria. This proposed AD would continue to require, 
depending on the results of the BSI, replacement of the LPC R1. This 
proposed AD would also require removal and replacement of certain CIC 
assemblies, identified by part number, with a CIC assembly eligible for 
installation.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 114 engines installed on airplanes of U.S. registry. The FAA 
estimates that five percent of engines installed on airplanes of U.S. 
registry would require BSI of the LPC R1, as proposed in paragraph 
(g)(3) of this AD, after installation of the EEC FADEC software version 
eligible for installation.
    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
----------------------------------------------------------------------------------------------------------------
Replace EEC FADEC software............  2 work-hours x $85 per                $0            $170         $19,380
                                         hour = $170.
BSI of the LPC R1.....................  2 work-hours x $85 per                 0             170             969
                                         hour = $170.
Replace CIC assembly..................  428 work-hours x $85 per         124,522         160,902      18,342,828
                                         hour = $36,380.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
inspection if certain Onboard Maintenance Message fault codes are 
displayed or if any necessary replacement would be required based on 
the results of the proposed inspection. The agency has no way of 
determining the number of aircraft that might need these replacements 
or inspections:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace LPC R1................................  40 work-hours x $85 per hour =          $156,000        $159,400
                                                 $3,400.
BSI of the LPC R1 if Onboard Maintenance        2 work-hours x $85 per hour =                  0             170
 Message fault codes are displayed and meet      $170.
 specified criteria.
----------------------------------------------------------------------------------------------------------------

    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some of the costs of this 
proposed AD may be covered under warranty, thereby reducing the cost 
impact on affected individuals.

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 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 that the proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Would not affect intrastate aviation in Alaska, and
    (3) Would not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

[[Page 19408]]

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:
0
a. Removing Airworthiness Directive 2021-14-06, Amendment 39-21633 (86 
FR 36061, July 8, 2021); and
0
b. Adding the following new airworthiness directive:

Pratt & Whitney: Docket No. FAA-2022-0384; Project Identifier AD-
2022-00027-E.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) action by May 19, 2022.

(b) Affected ADs

    This AD replaces AD 2021-14-06, Amendment 39-21633 (86 FR 36061, 
July 8, 2021).

(c) Applicability

    This AD applies to Pratt & Whitney PW1519G, PW1521G, PW1521G-3, 
PW1521GA, PW1524G, PW1524G-3, PW1525G, PW1525G-3, PW1919G, PW1921G, 
PW1922G, PW1923G, and PW1923G-A model turbofan engines.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by reports of in-flight shutdowns due to 
failure of the low-pressure compressor (LPC) rotor 1 (R1) and by 
subsequent findings of cracked LPC R1s during inspection. The FAA is 
issuing this AD to prevent failure of the LPC R1. The unsafe 
condition, if not addressed, could result in an uncontained release 
of the LPC R1, damage to the engine, damage to the airplane, and 
loss of the airplane.

(f) Compliance

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

(g) Required Actions

    (1) For PW1519G, PW1521G, PW1521G-3, PW1521GA, PW1524G, PW1524G-
3, PW1525G, and PW1525G-3 model turbofan engines with installed 
electronic engine control (EEC) full authority digital electronic 
control (FADEC) software earlier than EEC FADEC software version 
V2.11.10.4, before further flight, remove the EEC FADEC software and 
install EEC FADEC software version eligible for installation.
    (2) For PW1919G, PW1921G, PW1922G, PW1923G, and PW1923G-A model 
turbofan engines with installed EEC FADEC software earlier than EEC 
FADEC software version V9.5.6.7, before further flight, remove the 
EEC FADEC software and install EEC FADEC software version eligible 
for installation.
    (3) For the model turbofan engines identified in paragraphs 
(g)(1) and (g)(2) of this AD, after installation of the EEC FADEC 
software version eligible for installation as required by paragraphs 
(g)(1) and (g)(2) of this AD, before further flight, perform a one-
time borescope inspection (BSI) of the LPC R1 for damage and cracks 
at the following LPC R1 locations:
    (i) The blade tip;
    (ii) The leading edge;
    (iii) The leading edge fillet to rotor platform radius; and
    (iv) The airfoil convex side root fillet to rotor platform 
radius.
    (4) Based on the results of the BSI required by paragraph (g)(3) 
of this AD, before further flight, remove and replace the LPC R1 if:
    (i) There is damage on an LPC R1 that exceeds serviceable 
limits; or
    (ii) Any crack in the LPC R1 exists.
    Note 1 to paragraph (g)(4): Guidance on determining the 
serviceable limits in paragraphs (g)(4) and (6) of this AD can be 
found in Pratt & Whitney (PW) Service Bulletin (SB) PW1000G-A-72-00-
0125-00A-930A-D, Issue No. 004, dated October 13, 2021, and PW SB 
PW1000G-A-72-00-0075-00B-930A-D, Issue No. 004, dated July 21, 2021.
    (5) For PW1519G, PW1521G, PW1521G-3, PW1521GA, PW1524G, PW1524G-
3, PW1525G, and PW1525G-3 model turbofan engines with EEC FADEC 
software version V2.11.10.4 or later installed, within 15 flight 
cycles after receipt of Onboard Maintenance Message fault code 
7100F0029 or 7100F0030, perform a BSI of the LPC R1 for damage and 
cracks at the locations specified in paragraph (g)(3) of this AD if 
the fault code is displayed on the Active Failure Messages and meets 
the following criteria:
    (i) N1 Exceedance is above 95.2%;
    (ii) N1 Exceedance occurred above 29,100 feet;
    (iii) N1 Exceedance occurs for a duration of 40 seconds (15 
seconds of cockpit display) or more during any flight; and
    (iv) Compressor intermediate case (CIC) assembly installed has 
part number (P/N) 5379926, P/N 5379940, P/N 5379946, or P/N 5379926-
001.
    Note 2 to paragraph (g)(5): Guidance on determining the N1 
Exceedance duration can be found in Section PW1000G-A-72-00-00-02A-
0B5A-A of PW engine maintenance manual (EMM), Issue No. 016, dated 
January 15, 2021.
    Note 3 to paragraph (g)(5): Guidance on performing the BSI can 
be found in Section PW1000G-A-72-31-00-00A-312A-D of PW EMM, Issue 
No. 017, dated March 19, 2021.
    (6) Based on the results of the BSI required by paragraph (g)(5) 
of this AD, before further flight, remove and replace the LPC R1 if:
    (i) There is damage on an LPC R1 that exceeds serviceable 
limits; or
    (ii) Any crack in the LPC R1 exists.
    (7) For all affected model turbofan engines, at the next engine 
shop visit after the effective date of this AD, remove CIC assembly 
with P/N 5379926, P/N 5379940, P/N 5379946, or P/N 5379926-001 and 
replace with a CIC assembly eligible for installation.
    (8) For PW1519G, PW1521G, PW1521G-3, PW1521GA, PW1524G, PW1524G-
3, PW1525G, and PW1525G-3 model turbofan engines with installed EEC 
FADEC software version V2.11.10.4, at the next engine shop visit 
after the effective date of this AD, remove the EEC FADEC software 
and install EEC FADEC software version eligible for installation.
    (9) For PW1919G, PW1921G, PW1922G, PW1923G, and PW1923G-A model 
turbofan engines with installed EEC FADEC software version V9.5.6.7, 
at the next engine shop visit after the effective date of this AD, 
remove the EEC FADEC software and install EEC FADEC software version 
eligible for installation.

(h) Definitions

    (1) For the purpose of this AD, ``EEC FADEC software version 
eligible for installation'' is EEC FADEC software version V2.11.12.4 
or later for PW1519G, PW1521G, PW1521G-3, PW1521GA, PW1524G, 
PW1524G-3, PW1525G, and PW1525G-3 model turbofan engines, and EEC 
FADEC software version V9.6.5.6 or later for PW1919G, PW1921G, 
PW1922G, PW1923G, and PW1923G-A model turbofan engines.
    (2) 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 the LPC Flange 1 or separation of the LPC Flange 4, 
except for the following situations, which do not constitute an 
engine shop visit.
    (i) Separation of engine flanges solely for the purposes of 
transportation without subsequent engine maintenance.
    (ii) Separation of engine flanges solely for the purpose of 
replacing the fan without subsequent maintenance.
    (3) For the purpose of this AD, a ``CIC assembly eligible for 
installation'' is any CIC assembly that does not have P/N 5379926, 
P/N 5379940, P/N 5379946, or P/N 5379926-001.

(i) 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 (j)(1) of this AD and email 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.

[[Page 19409]]

(j) Related Information

    (1) For more information about this AD, contact Mark Taylor, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7229; email: 
[email protected].
    (2) For service information identified in this AD, contact Pratt 
& Whitney, 400 Main Street, East Hartford, CT 06118; phone: (800) 
565-0140; email: [email protected]; website: http://fleetcare.pw.utc.com.
    (3) You may view this referenced service information at the FAA, 
Airworthiness Products Section, Operational Safety Branch, 1200 
District Avenue, Burlington, MA 01803. For information on the 
availability of this material at the FAA, call (817) 222-5110.

    Issued on March 25, 2022.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-07013 Filed 4-1-22; 8:45 am]
BILLING CODE 4910-13-P