Document ID: FAA-2021-0515-0004
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Pratt and Whitney Turbofan Engines
Posted Date: 2021-09-22T04:00Z

[Federal Register Volume 86, Number 181 (Wednesday, September 22, 2021)]
[Rules and Regulations]
[Pages 52600-52603]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-20365]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0515; Project Identifier AD-2021-00191-E; 
Amendment 39-21739; AD 2021-20-01]
RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Pratt & Whitney PW1500G and PW1900G series turbofan engines with a 
certain high-pressure turbine (HPT) 1st-stage hub or HPT rotor 1st-
stage blade retaining plate installed. This AD was prompted by a report 
from the manufacturer who determined that the HPT 1st-stage hub and HPT 
rotor 1st-stage blade retaining plate fail to meet the published life-
cycle limits for each part. This AD requires removal and replacement of 
the HPT 1st-stage hub and HPT rotor 1st-stage blade retaining plate 
prior to reaching certain cycle limits. The FAA is issuing this AD to 
address the unsafe condition on these products.

DATES: This AD is effective October 27, 2021.

ADDRESSES: For service information identified in this final rule, 
contact Pratt & Whitney, 400 Main Street, East Hartford, CT 06118; 
phone: (800) 565-

[[Page 52601]]

0140; fax: (860) 565-5442; email: help24@prattwhitney.com; website: 
https://fleetcare.prattwhitney.com. You may view this 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 (781) 
238-7759. It is also available at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0515.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0515; 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: Mark Taylor, Aviation Safety Engineer, 
ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 
(781) 238-7229; fax: (781) 238-7199; email: Mark.Taylor@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to all Pratt & Whitney 
PW1500G and PW1900G series turbofan engines with a certain HPT 1st-
stage hub or HPT rotor 1st-stage blade retaining plate installed. The 
NPRM published in the Federal Register on June 29, 2021 (86 FR 34166). 
The NPRM was prompted by a report from the manufacturer who determined 
that the HPT 1st-stage hub and HPT rotor 1st-stage blade retaining 
plate fail to meet the published life-cycle limits for each part. In 
the NPRM, the FAA proposed to require removal and replacement of the 
HPT 1st-stage hub and HPT rotor 1st-stage blade retaining plate prior 
to reaching certain cycle limits. The FAA is issuing this AD to address 
the unsafe condition on these products.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from two commenters. The commenters were 
Delta Air Lines, Inc. (DAL) and the Air Line Pilots Association, 
International (ALPA). The following presents the comments received on 
the NPRM and the FAA's response to each comment.

Request To Correct Required Actions

    DAL requested that the FAA change paragraph (g)(1)(ii) of this AD 
from removing the affected part and replacing with a part eligible for 
installation ``at the next engine shop visit after accumulating 4,700 
CSN. . .'' to ``at the next engine shop visit after accumulating 4,960 
CSN. . .'' to mirror the 4,960 CSN listed earlier in the paragraph. DAL 
suggested that ``4,700 CSN'' is a typographical error.
    The FAA disagrees that ``4,700 CSN'' is a typographical error. It 
is the cyclic value at which point certain HPT parts are to be removed 
from service. In contrast, ``4,960 CSN on the effective date of this 
AD'' is a calculated point at which HPT-part removal requirements 
transition from the requirements of paragraph (g)(1)(ii) of this AD to 
the requirements of paragraph (g)(1)(iii) of this AD. ``4,960 CSN'' and 
``4,700 CSN'' are different in their function and how they are 
calculated. The FAA did not change this AD.

Support for the AD

    ALPA expressed support for the NPRM as written.

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, and determined that air safety requires adopting this AD as 
proposed. Accordingly, the FAA is issuing this AD to address the unsafe 
condition on these products. This AD is adopted as proposed in the 
NPRM.

Related Service Information

    The FAA reviewed Pratt & Whitney Service Bulletin (SB) PW1000G-A-
72-00-0115-00B-930A-D, Issue No. 001, dated April 26, 2021, and Pratt & 
Whitney SB PW1000G-A-72-00-0168-00A-930A-D, Issue No. 001, dated April 
26, 2021. These SBs describe procedures for removing and replacing the 
HPT 1st-stage hub and HPT rotor 1st-stage blade retaining plate.

Costs of Compliance

    The FAA estimates that this AD affects 88 engines installed on 
airplanes of U.S. registry. The FAA estimates that in most cases the 
affected HPT 1st-stage hub and the affected HPT 1st-stage blade 
retaining plate will both be replaced during the same disassembly of 
the engine. This cost estimate therefore reflects the cost of replacing 
both parts during the same engine disassembly.
    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 HPT 1st-stage hub and HPT       300 work-hours x $85 per         $86,252        $111,752      $9,834,176
 rotor 1st-stage blade retaining plate   hour = $25,500.
 (pro-rated part cost).
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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 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

    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

[[Page 52602]]

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 adding the following new airworthiness 
directive:

2021-20-01 Pratt & Whitney: Amendment 39-21739; Docket No. FAA-2021-
0515; Project Identifier AD-2021-00191-E.

(a) Effective Date

    This airworthiness directive (AD) is effective October 27, 2021.

(b) Affected ADs

    None.

(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 with a high-
pressure turbine (HPT) 1st-stage hub, part number (P/N) 30G5701, or 
an HPT rotor 1st-stage blade retaining plate, P/N 30G1692, 
installed.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by a report from the manufacturer who 
determined that the HPT 1st-stage hub and HPT rotor 1st-stage blade 
retaining plate fail to meet the published life-cycle limits for 
each part. The FAA is issuing this AD to prevent failure of the HPT 
1st-stage hub or HPT rotor 1st-stage blade retaining plate. The 
unsafe condition, if not addressed, could result in the release of 
the HPT 1st-stage hub or HPT rotor 1st-stage blade retaining plate, 
damage to the engine, and damage to the aircraft.

(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, and 
PW1524G-3 model turbofan engines:
    (i) For an affected HPT 1st-stage hub and an affected HPT rotor 
1st-stage blade retaining plate with 3,000 cycles since new (CSN) or 
fewer on the effective date of this AD, before the affected part 
exceeds 4,700 CSN, remove the affected part, as applicable, and 
replace with a part eligible for installation.
    (ii) For an affected HPT 1st-stage hub and an affected HPT rotor 
1st-stage blade retaining plate with greater than 3,000 CSN but 
fewer than 4,960 CSN on the effective date of the AD, at the next 
engine shop visit after accumulating 4,700 CSN or before the 
affected part exceeds 5,260 CSN, whichever occurs first, remove the 
affected part, as applicable, and replace with a part eligible for 
installation.
    (iii) For an affected HPT 1st-stage hub and an affected HPT 
rotor 1st-stage blade retaining plate with 4,960 CSN or greater on 
the effective date of the AD, at the next engine shop visit or 
within 300 cycles after the effective date of this AD, whichever 
occurs first, remove the affected part, as applicable, and replace 
with a part eligible for installation.
    (2) For PW1919G and PW1921G model turbofan engines:
    (i) For an affected HPT 1st-stage hub and an affected HPT rotor 
1st-stage blade retaining plate with 3,000 CSN or fewer on the 
effective date of this AD, before the affected part exceeds 4,700 
CSN, remove the affected part, as applicable, and replace with a 
part eligible for installation.
    (ii) For an affected HPT 1st-stage hub and an affected HPT rotor 
1st-stage blade retaining plate with greater than 3,000 CSN but 
fewer than 4,700 CSN on the effective date of the AD, at the next 
engine shop visit after the affected part accumulates 4,700 CSN or 
before the affected part exceeds 5,000 CSN, whichever occurs first, 
remove the affected part, as applicable, and replace with a part 
eligible for installation.
    (iii) For an affected HPT 1st-stage hub and an affected HPT 
rotor 1st-stage blade retaining plate with 4,700 CSN or greater on 
the effective date of the AD, at the next engine shop visit or 
within 300 cycles after the effective date of this AD, whichever 
occurs first, remove the affected part, as applicable, and replace 
with a part eligible for installation.
    (3) For PW1525G and PW1525G-3 model turbofan engines:
    (i) Before the affected HPT 1st-stage hub and affected HPT rotor 
1st-stage blade retaining plate exceeds 2,800 CSN, respectively, or 
within 300 cycles after the effective date of this AD, whichever 
occurs later, remove the affected part, as applicable, and replace 
with a part eligible for installation.
    (ii) [Reserved]
    (4) For PW1922G, PW1923G, and PW1923G-A model turbofan engines:
    (i) Before the affected HPT 1st-stage hub and affected HPT rotor 
1st-stage blade retaining plate exceeds 3,000 CSN, respectively, or 
within 300 cycles after the effective date of this AD, whichever 
occurs later, remove the affected part, as applicable, and replace 
with a part eligible for installation.
    (ii) [Reserved]

(h) Definitions

    (1) 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 case flanges, except for 
the following, which do not constitute an engine shop visit:
    (i) Separation of engine flanges solely for the purposes of 
transportation without subsequent maintenance does not constitute an 
engine shop visit.
    (ii) Separation of engine flanges solely for the purpose of 
replacing the fan without subsequent maintenance does not constitute 
an engine shop visit.
    (2) For the purpose of this AD, a ``part eligible for 
installation'' is:
    (i) For PW1519G, PW1521G, PW1521G-3, PW1521GA, PW1524G, PW1524G-
3, PW1919G, and PW1921G model turbofan engines:
    (A) Any HPT 1st-stage hub with P/N 30G5701 with 4,700 CSN or 
fewer, or with a P/N not listed in this AD.
    (B) Any HPT rotor 1st-stage blade retaining plate with P/N 
30G1692 with 4,700 CSN or fewer, or with a P/N not listed in this 
AD.
    (ii) For PW1525G and PW1525G-3 model turbofan engines:
    (A) Any HPT 1st-stage hub with P/N 30G5701 with 2,800 CSN or 
fewer, or with a P/N not listed in this AD.
    (B) Any HPT rotor 1st-stage blade retaining plate with P/N 
30G1692 with 2,800 CSN or fewer, or with a P/N not listed in this 
AD.
    (iii) For PW1922G, PW1923G, and PW1923G-A model turbofan 
engines:
    (A) Any HPT 1st-stage hub with P/N 30G5701 with 3,000 CSN or 
fewer, or with a P/N not listed in this AD.
    (B) Any HPT rotor 1st-stage blade retaining plate with P/N 
30G1692 with 3,000 CSN or fewer, or with a P/N not listed in this 
AD.

(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) of this AD. You may email your request 
to: ANE-AD-AMOC@faa.gov.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager

[[Page 52603]]

of the local flight standards district office/certificate holding 
district office.

(j) Related Information

    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; fax: (781) 238-7199; 
email: Mark.Taylor@faa.gov.

(k) Material Incorporated by Reference

    None.

    Issued on September 14, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-20365 Filed 9-21-21; 8:45 am]
BILLING CODE 4910-13-P