Airworthiness Directives; Pratt & Whitney Turbofan Engines

[Federal Register Volume 86, Number 128 (Thursday, July 8, 2021)]
[Rules and Regulations]
[Pages 36061-36064]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-13873]



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Federal Register / Vol. 86, No. 128 / Thursday, July 8, 2021 / Rules 
and Regulations

[[Page 36061]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0191; Project Identifier AD-2020-01492-E; 
Amendment 39-21633; AD 2021-14-06]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2019-21-11 
and AD 2020-07-02. AD 2019-21-11 applied 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 2020-07-02 applied to all PW PW1519G, PW1521G, 
PW1521G-3, PW1521GA, PW1524G, PW1524G-3, PW1525G, and PW1525G-3 model 
turbofan engines. AD 2019-21-11 required initial and repetitive 
borescope inspections (BSIs) of the low-pressure compressor (LPC) rotor 
1 (R1) and, depending on the results of the inspections, replacement of 
the LPC. AD 2020-07-02 required the removal from service of certain 
electronic engine control (EEC) full authority digital electronic 
control (FADEC) software and the installation of a software version 
eligible for installation. This AD continues to require repetitive BSIs 
of certain LPC R1s until replacement of EEC FADEC software with the 
updated software. This AD 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. The FAA is issuing 
this AD to address the unsafe condition on these products.

DATES: This AD is effective August 12, 2021.

ADDRESSES: For service information identified in this final rule, 
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 (781) 238-7759. It is also available at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-
0191.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0191; 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, any 
comments received, and other information. The address for Docket 
Operations 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: Nicholas Paine, Aviation Safety 
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; 
phone: (781) 238-7116; fax: (781) 238-7199; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to supersede AD 2019-21-11, Amendment 39-19777 (84 FR 
57813, October 29, 2019), (AD 2019-21-11) and AD 2020-07-02, Amendment 
39-21106 (85 FR 17742, March 31, 2020), (AD 2020-07-02). AD 2019-21-11 
applied to certain PW PW1519G, PW1521G, PW1521GA, PW1524G, PW1525G, 
PW1521G-3, PW1524G-3, PW1525G-3, PW1919G, PW1921G, PW1922G, PW1923G, 
and PW1923G-A model turbofan engines. AD 2020-07-02 applied to all PW 
PW1519G, PW1521G, PW1521G-3, PW1521GA, PW1524G, PW1524G33, PW1525G, and 
PW1525G33 model turbofan engines.
    The NPRM published in the Federal Register on March 26, 2021 (86 FR 
16137). The NPRM 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. In the 
NPRM, the FAA proposed to retain certain requirements of AD 2019-21-11 
and none of the requirements of AD 2020-07-02. In the NPRM, the FAA 
proposed to continue to require a BSI of certain LPC R1s for damage and 
cracks and, depending on the results of the BSI, replacement of the LPC 
R1. In the NPRM, the FAA proposed to continue to require repetitive 
BSIs of certain LPC R1s until replacement of the EEC FADEC software 
with the updated software. In the NPRM, the FAA also proposed to 
require a BSI of the LPC R1 after installation of the updated EEC FADEC 
software if certain Onboard Maintenance Message fault codes are 
displayed and meet specified criteria.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from two commenters. The commenters were 
Air Line Pilots Association, International (ALPA) and Delta Air Lines, 
Inc. (DAL). ALPA supported the proposal without change. DAL supported 
the proposal but recommended certain changes. The following presents 
the comments received on the NPRM and the FAA's response to each 
comment.

Request To Correct the Effective Date of AD 2019-19-11

    DAL requested that the FAA correct the reference to the effective 
date of AD 2019-19-11, in paragraph (g)(1)(i) of this AD from October 
29, 2019, to September 26, 2019 (the effective date of AD 2019-19-11).
    The FAA agrees and has revised paragraph (g)(1)(i) of this AD as 
requested. This change adds no additional burden on any operator who is 
required to comply with this AD.

[[Page 36062]]

Request To Allow Use of Later Revisions of Service Information

    DAL requested that the FAA add the phrase ``or later'' after PW 
Section PW1000G-A-72-00-00-02A-0B5A-A of PW Engine Maintenance Manual 
(EMM), Issue No. 016, dated January 15, 2021, and PW Section PW1000G-A-
72-31-00-00A-312A-D of PW EMM, Issue No. 016, dated January 11, 2021, 
referenced in Notes 2 and 3 to paragraph (g)(6) of this AD. DAL stated 
that if a maintenance technician were troubleshooting Onboard 
Maintenance Message fault code 7100F0029 or 7100F0030, the maintenance 
technician would be guided to the latest issue of the publication.
    The FAA disagrees to add the phrase ``or later'' to the required 
actions section as requested by DAL. Notes 2 and 3 to paragraph (g)(6) 
of this AD, which contain references to the sections of the EMM 
specified by DAL, provide guidance for both determining the N1 
Exceedance duration and for performing the BSI. This AD does not 
mandate the use of specific manual revisions for purposes of compliance 
with the required actions.

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, and determined that air safety requires adopting the AD as 
proposed. Accordingly, the FAA is issuing this AD to address the unsafe 
condition on these products. Except for minor editorial changes, and 
any other changes described previously, this AD is adopted as proposed 
in the NPRM. None of the changes will increase the economic burden on 
any operator.

Related Service Information

    The FAA reviewed Pratt & Whitney Service Bulletin (SB) PW1000G-A-
72-00-0125-00A-930A-D, Issue No. 002, dated October 24, 2019; Pratt & 
Whitney SB PW1000G-A-72-00-0075-00B-930A-D, Issue No. 003, dated 
October 24, 2019; Pratt & Whitney SB PW1000G-A-73-00-0044-00A-930A-D, 
Issue No. 004, dated February 23, 2021; and Pratt & Whitney SB PW1000G-
A-73-00-0023-00B-930A-D, Issue No. 002, dated February 22, 2021. The 
FAA also reviewed Section PW1000G-A-72-00-00-02A-0B5A-A of Pratt & 
Whitney EMM, Issue No. 016, dated January 15, 2021; and Section 
PW1000G-A-72-31-00-00A-312A-D of Pratt & Whitney EMM, Issue No. 016, 
dated January 11, 2021.
    Pratt & Whitney SBs PW1000G-A-72-00-0125-00A-930A-D, Issue No. 002, 
dated October 24, 2019, and PW1000G-A-72-00-0075-00B-930A-D, Issue No. 
003, dated October 24, 2019, describe procedures for performing initial 
and repetitive BSI of certain LPC R1s. Pratt & Whitney SB PW1000G-A-73-
00-0044-00A-930A-D, Issue No. 004, dated February 23, 2021, describes 
procedures for replacing or modifying the EEC to incorporate EEC FADEC 
software version V2.11.10.4. Pratt & Whitney SB PW1000G-A-73-00-0023-
00B-930A-D, Issue No. 002, dated February 22, 2021, describes 
procedures for replacing or modifying the EEC to incorporate EEC FADEC 
software version V9.5.6.7.
    Section PW1000G-A-72-00-00-02A-0B5A-A of Pratt & Whitney 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 Pratt & Whitney EMM, Issue No. 016, dated January 11, 2021, 
describes procedures for performing a BSI of the LPC.

Interim Action

    The FAA considers this AD to be an interim action. If final 
corrective action is later identified, the FAA might consider 
additional rulemaking.

Costs of Compliance

    The FAA estimates that this AD affects 94 engines installed on 
airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this 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         $15,980
                                         hour = $170.
BSI per inspection cycle..............  2 work-hours x $85 per                 0             170          15,980
                                         hour = $170.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
replacements that would be required based on the results of the 
inspection. The agency has no way of determining the number of aircraft 
that might need this replacement:

                                               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.              $170.
----------------------------------------------------------------------------------------------------------------

    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some of the costs of this 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

[[Page 36063]]

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 has determined that 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) 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 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:
0
a. Removing Airworthiness Directive AD 2019-21-11, Amendment 39-19777 
(84 FR 57813, October 29, 2019); and AD 2020-07-02, Amendment 39-21106 
(85 FR 17742, March 31, 2020); and
0
b. Adding the following new airworthiness directive:

2021-14-06 Pratt & Whitney: Amendment 39-21633; Docket No. FAA-2021-
0191; Project Identifier AD-2020-01492-E.

(a) Effective Date

    This airworthiness directive (AD) is effective August 12, 2021.

(b) Affected ADs

    This AD replaces AD 2019-21-11, Amendment 39-19777 (84 FR 57813, 
October 29, 2019); and AD 2020-07-02, Amendment 39-21106 (85 FR 
17742, March 31, 2020).

(c) Applicability

    This AD applies to Pratt & Whitney (PW) 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 uncontained release of 
the LPC R1, damage to the engine, damage to the airplane, and loss 
of control of the airplane.

(f) Compliance

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

 (g) Required Actions

    (1) Except for those model turbofan engines identified in 
paragraph (g)(2) of this AD, perform a borescope inspection (BSI) of 
the LPC R1 for damage and cracks as follows:
    (i) For engines that have accumulated fewer than 300 flight 
cycles since new (CSN), perform a BSI within 50 flight cycles (FCs) 
from September 26, 2019 (the effective date of AD 2019-19-11), or 
before further flight, whichever occurs later.
    (ii) For engines that have accumulated fewer than 300 FCs since 
installation of V2.11.7 or V2.11.8 electronic engine control (EEC) 
full authority digital electronic control (FADEC) software, perform 
a BSI within 50 FCs from October 29, 2019 (the effective date of AD 
2019-21-11), or before further flight, whichever occurs later.
    (iii) Thereafter, at intervals not to exceed 50 FCs until the 
engine accumulates 300 flight CSN or accumulates 300 FCs since the 
installation of V2.11.7 or V2.11.8 EEC FADEC software, whichever 
occurs later, repeat the BSI for damage and cracks.
    (iv) Perform the BSI required by paragraphs (g)(1)(i) through 
(iii) of this AD at the following LPC R1 locations:
    (A) The blade tip;
    (B) The leading edge;
    (C) The leading edge fillet to rotor platform radius; and
    (D) The airfoil convex side root fillet to rotor platform 
radius.
    (2) For any affected PW model turbofan engine installed as a 
``zero time spare,'' except for PW1519G, PW1521GA, PW1919G, and 
PW1922G model turbofan engines, within 15 FCs from the effective 
date of this AD, and thereafter at intervals not to exceed 15 FCs 
until the engine accumulates 300 flight CSN, perform a BSI of the 
LPC R1 for damage and cracks at the locations in paragraph 
(g)(1)(iv) of this AD.
    (3) Based on the results of the BSIs required by paragraphs 
(g)(1) and (2) 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)(3): Guidance on determining the 
serviceable limits in paragraph (g)(3) of this AD can be found in PW 
Service Bulletin (SB) PW1000G-A-72-00-0125-00A-930A-D, Issue No. 
002, dated October 24, 2019, and PW SB PW1000G-A-72-00-0075-00B-
930A-D, Issue No. 003, dated October 24, 2019.
    (4) For PW PW1519G, PW1521G, PW1521G-3, PW1521GA, PW1524G, 
PW1524G-3, PW1525G, and PW1525G-3 model turbofan engines, within 120 
days from the effective date of this AD, remove the EEC FADEC 
software if the version is earlier than EEC FADEC software version 
V2.11.10.4 and install EEC FADEC software that is eligible for 
installation.
    (5) For PW PW1919G, PW1921G, PW1922G, PW1923G, and PW1923G-A 
model turbofan engines, within 120 days of the effective date of 
this AD, remove the EEC FADEC software if the version is earlier 
than EEC FADEC software version V9.5.6.7 and install EEC FADEC 
software that is eligible for installation.
    (6) For PW 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 FCs 
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 in paragraph (g)(1)(iv) 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; and
    (iii) N1 Exceedance occurs for a duration of 40 seconds (15 
seconds of cockpit display) or more during any flight.
    Note 2 to paragraph (g)(6): Guidance on determining the N1 
Exceedance duration can be found in PW 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)(6): Guidance on performing the BSI can 
be found in PW Section PW1000G-A-72-31-00-00A-312A-D of PW EMM, 
Issue No. 016, dated January 11, 2021.
    (7) As the result of the BSI of the LPC R1 required by paragraph 
(g)(6) 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.

 (h) Terminating Actions

    (1) For PW1519G, PW1521G, PW1521G-3, PW1521GA, PW1524G, PW1524G-
3, PW1525G, and PW1525G-3 model turbofan engines, the installation 
of EEC FADEC software required by paragraph (g)(4) of this AD 
terminates the repetitive BSI requirements of paragraphs (g)(1) and 
(2) of this AD.

[[Page 36064]]

    (2) For PW1919G, PW1921G, PW1922G, PW1923G, and PW1923G-A model 
turbofan engines, the installation of EEC FADEC software required by 
paragraph (g)(5) of this AD terminates the repetitive BSI 
requirements of paragraphs (g)(1) and (2) of this AD.

 (i) Installation Prohibition

    After the effective date of this AD, do not install EEC FADEC 
software earlier than version V2.11.10.4 or version V9.5.6.7 onto 
any engine identified in paragraph (c) of this AD.

 (j) Definitions

    (1) For the purpose of this AD, a ``zero time spare'' is an 
engine that had zero flight hours time-in-service when it was 
installed on an airplane after the airplane had entered service.
    (2) For the purpose of this AD, ``EEC FADEC software that is 
eligible for installation'' is EEC FADEC software version V2.11.10.4 
or later for PW1519G, PW1521G, PW1521G-3, PW1521GA, PW1524G, 
PW1524G-3, PW1525G, PW1525G-3 model turbofan engines and EEC FADEC 
software version V9.5.6.7 or later for PW1919G, PW1921G, PW1922G, 
PW1923G, and PW1923G-A model turbofan engines.

(k) 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 Related Information. 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.
    (3) AMOCs approved for AD 2019-21-11 (84 FR 57813, October 29, 
2019) are approved as AMOCs for the corresponding provisions of this 
AD except for paragraphs (g)(1)(i) through (iv) and (g)(3)(i) and 
(ii) of this AD.

(l) Related Information

    For more information about this AD, contact Nicholas Paine, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7116; fax: (781) 238-7199; 
email: [email protected].

(m) Material Incorporated by Reference

    None.

    Issued on June 23, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-13873 Filed 7-7-21; 8:45 am]
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