Document ID: FAA-2021-0511-0004
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Williams International Co., L.L.C. Turbofan Engines
Posted Date: 2022-04-14T04:00Z

[Federal Register Volume 87, Number 72 (Thursday, April 14, 2022)]
[Proposed Rules]
[Pages 22153-22156]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-07822]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0511; Project Identifier AD-2020-01229-E]
RIN 2120-AA64

Airworthiness Directives; Williams International Co., L.L.C. 
Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (SNPRM).

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SUMMARY: The FAA is revising a notice of proposed rulemaking (NPRM) 
that applied to certain Williams International Co., L.L.C. (Williams) 
FJ44-2A, FJ44-2C, FJ44-3A, and FJ44-3A-24 model turbofan engines. This 
action revises the NPRM by expanding the applicability, updating the 
estimated costs information, updating the compliance time, and adding 
an installation prohibition. This action also revises the NPRM by 
updating the service information references. The FAA is proposing this 
airworthiness directive (AD) to address the unsafe condition on these 
products. Since these actions would impose an additional burden over 
those in the NPRM, the agency is requesting comments on this SNPRM.

DATES: The FAA must receive comments on this SNPRM by May 31, 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 SNPRM, contact Williams 
International, Product Support, 2000 Centerpoint Parkway, Pontiac, MI 
48341; phone: (800) 859-3544; website: http://www.williams-int.com/product-support. You may view this service information at the FAA, 
Chicago ACO, 2300 East Devon Avenue, Des Plaines, IL 60018. 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-2021-0511; 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 SNPRM, any 
comments received, and other information. The street address for Docket 
Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Kyle Bush, Aviation Safety Engineer, 
Chicago ACO, FAA, 2300 East Devon Avenue, Des Plaines, IL 60018; phone: 
(847) 294-7870; 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-2021-0511; Project Identifier 
AD-2020-01229-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 again revise this 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 received 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 SNPRM 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 SNPRM, 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 SNPRM. Submissions containing CBI should 
be sent to Kyle Bush, Aviation Safety Engineer, Chicago ACO, FAA, 2300 
East Devon Avenue, Des Plaines, IL 60018. 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 an NPRM to amend 14 CFR part 39 by adding an AD that 
would apply to Williams FJ44-2A, FJ44-2C, FJ44-3A, and FJ44-3A-24 model 
turbofan engines. The NPRM published in the Federal Register on June 
25, 2021 (86 FR 33579). The NPRM was prompted by a report of cracks in 
the high-pressure turbine (HPT) disk posts and failure of an HPT disk 
post, resulting in the contained fracture of an HPT disk post and 
blade. Williams initiated an investigation to understand the root cause 
of the cracks and to determine the necessary corrective action. 
Metallurgical evaluation showed cracking related to intergranular 
oxidation related to HPT disk post metal temperatures.
    As a result of this investigation, Williams determined the root 
cause of this cracking was due to higher HPT disk post temperatures and 
a difference in manufacturing processes. Williams determined that these 
cracks have only occurred on HPT disks with part number (P/N) 67093 
installed on FJ44-2A or FJ44-2C model turbofan engines. Williams 
subsequently published service information specifying procedures to 
remove the HPT disk, P/N 67093. In the NPRM, the FAA proposed to 
require removing the HPT disk, P/N 67093, from service before reaching 
its new life limit and replacing it with a part eligible for 
installation.

Actions Since the NPRM Was Issued

    Since the FAA issued the NPRM, Williams notified the FAA that 
revised service information was available. The revised service 
information, Williams International Service Bulletin (SB) WISB-72-1032, 
Revision 2, dated June 4, 2020, adds additional serial-numbered FJ44-
2A, FJ44-2C, and FJ44-3A model turbofan engines to the effectivity and 
updates the compliance time for replacing the HPT disk. The FAA 
determined that the additional

[[Page 22154]]

serial-numbered FJ44-2A, FJ44-2C, and FJ44-3A model turbofan engines 
are susceptible to the same unsafe condition. Therefore, the FAA 
revised the applicability of this proposed AD to include FJ44-2A, FJ44-
2C, FJ44-3A, and FJ44-3A-24 model turbofan engines with an engine 
serial number identified in paragraph 1.A., Effectivity, of Williams 
International SB WISB-72-1032, Revision 2, dated June 4, 2020, with an 
installed HPT disk, P/N 67093. In addition, the FAA revised the 
estimated number of affected engines installed on airplanes of U.S. 
registry from 213 engines to 242 engines, updated the compliance time 
specified in Table 1 to Paragraph (g), and added an installation 
prohibition paragraph to this proposed AD. Finally, the FAA revised all 
references to the service information in this AD.

Comments

    The FAA received a comment from one commenter on the NPRM, 
Williams. The following presents the comment received on the NPRM and 
the FAA's response to the comment.

Request That the NPRM Reflect Current Service Document Revisions

    Williams requested that the NPRM be revised to reflect the 
specified procedures of the current service document revisions, 
Williams International SB WISB-72-1032, Revision 2, dated June 4, 2020, 
and Williams International SB WISB-72-1034, Revision 3, dated July 2, 
2021.
    The FAA agrees. The FAA has revised this proposed AD to include 
Williams International SB WISB-72-1032, Revision 2, dated June 4, 2020, 
and Williams International SB WISB-72-1034, Revision 3, dated July 2, 
2021.

Other Differences Between This SNPRM and the NPRM

    In this SNPRM, the FAA has replaced the term ``life limit'' with 
``defined life cycles,'' where appropriate. In this SNPRM, the FAA has 
replaced all instances of ``resulting in the release of an HPT blade'' 
to ``resulting in the contained fracture of an HPT disk post and 
blade.''

FAA's Determination

    The FAA is proposing this AD after determining the unsafe condition 
described previously is likely to exist or develop in other products of 
the same type design. Certain changes described above expand the scope 
of the NPRM. As a result, it is necessary to reopen the comment period 
to provide additional opportunity for the public to comment on this 
SNPRM.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Williams International SB WISB-72-1032, Revision 
2, dated June 4, 2020. This service information specifies procedures 
for removing and replacing the HPT rotor assemblies that include HPT 
disk, P/N 67093. The service information also provides instructions for 
incorporating the latest HPT combustor/fuel slinger module on FJ44-2A 
and FJ44-2C model turbofan engines. 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 
ADDRESSES.

Other Related Service Information

    The FAA reviewed Williams International SB WISB-72-1034, Revision 
3, dated July 2, 2021. This service information describes procedures 
for re-identifying the HPT rotor assembly and HPT disk.

Proposed AD Requirements in This SNPRM

    This proposed AD would require removing the HPT disk, P/N 67093, 
from service before reaching defined cycle limits and replacing it with 
a part eligible for installation.

Differences Between This SNPRM and the Service Information

    The Accomplishment Instructions, paragraph 2.D., of Williams 
International SB WISB-72-1032, Revision 2, dated June 4, 2020, 
specifies procedures for replacing or reworking the HPT combustor/fuel 
slinger module on FJ44-2A and FJ44-2C model turbofan engines, while 
this proposed AD would not mandate that action. The FAA has determined 
that replacement or rework of the HPT combustor/fuel slinger module is 
not necessary to resolve the unsafe condition in this proposed AD.
    The Accomplishment Instructions, paragraphs 2.C. and E. and 3.C. 
and D., of Williams International SB WISB-72-1032, Revision 2, dated 
June 4, 2020, specify procedures for removing and replacing the HP 
turbine rotor assembly containing HPT disk, P/N 67093, whereas this 
proposed AD would mandate removing and replacing the HPT disk, P/N 
67093. Although removing the HPT rotor assembly is a necessary step in 
the replacement of the HPT disk, this proposed AD only requires 
replacement of the HPT disk to resolve the unsafe condition addressed 
by this proposed AD.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 242 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
--------------------------------------------------------------------------------------------------------------------------------------------------------
Remove and replace the HPT disk..............  33 work-hours x $85 per hour = $2,805....................         $16,694         $19,499      $4,718,758
--------------------------------------------------------------------------------------------------------------------------------------------------------

    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 operators.

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.

[[Page 22155]]

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) 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.

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:

Williams International Co., L.L.C.: Docket No. FAA-2021-0511; 
Project Identifier AD-2020-01229-E.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by May 31, 2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Williams International Co., L.L.C. (Williams) 
FJ44-2A, FJ44-2C, FJ44-3A, and FJ44-3A-24 model turbofan engines 
with an engine serial number identified in paragraph 1.A., 
Effectivity, of Williams International Service Bulletin WISB-72-
1032, Revision 2, dated June 4, 2020 (the SB), with an installed 
high-pressure turbine (HPT) disk, part number (P/N) 67093.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by a report of cracks in the HPT disk posts 
and failure of an HPT disk post, resulting in the contained fracture 
of an HPT disk post and blade. The FAA is issuing this AD to prevent 
cracking and failure of the HPT disk posts. The unsafe condition, if 
not addressed, could result in release of the HPT blade, 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) For FJ44-2A and FJ44-2C model turbofan engines, within the 
compliance times specified in Table 1 to Paragraph (g) of this AD, 
remove the affected HPT disk from service and replace it with a part 
eligible for installation using paragraphs 2.C. and E., 
Accomplishment Instructions--FJ44-2A & FJ44-2C, of the SB.
    (2) For FJ44-3A and FJ44-3A-24 model turbofan engines, within 
the compliance times specified in Table 1 to Paragraph (g) of this 
AD, remove the affected HPT disk from service and replace it with a 
part eligible for installation using paragraphs 3.C. and D., of the 
SB.
[GRAPHIC] [TIFF OMITTED] TP14AP22.043

(h) Installation Prohibition

    After the effective date of this AD, do not install onto any 
engine an HPT disk with P/N 67093.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Chicago ACO, 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.
    (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.

(j) Related Information

    (1) For more information about this AD, contact Kyle Bush, 
Aviation Safety Engineer, Chicago ACO, FAA, 2300 East Devon Avenue, 
Des Plaines, IL 60018; phone: (847) 294-7870; email: 
[email protected].
    (2) For service information identified in this AD, contact 
Williams International, Product Support, 2000 Centerpoint Parkway, 
Pontiac, MI 48341; phone: (800) 859-3544; website: http://www.williams-int.com/product-support. 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.

[[Page 22156]]

    Issued on April 7, 2022.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-07822 Filed 4-13-22; 8:45 am]
BILLING CODE 4910-13-P