Proposed Rule2021-13516
Airworthiness Directives; Williams International Co., L.L.C. Turbofan Engines
Primary source
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Published
June 25, 2021
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for certain Williams International Co., L.L.C. (Williams) FJ44-2A, FJ44-2C, FJ44-3A, and FJ44-3A-24 model turbofan engines. This proposed AD was prompted by a report of cracks in high-pressure turbine (HPT) disk posts and failure of an HPT disk post. This proposed AD would require the removal and replacement of the affected HPT disk before reaching its new life limit. The FAA is proposing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 86 Issue 120 (Friday, June 25, 2021)</title>
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[Federal Register Volume 86, Number 120 (Friday, June 25, 2021)]
[Proposed Rules]
[Pages 33579-33581]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-13516]
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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: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Williams International Co., L.L.C. (Williams) FJ44-2A,
FJ44-2C, FJ44-3A, and FJ44-3A-24 model turbofan engines. This proposed
AD was prompted by a report of cracks in high-pressure turbine (HPT)
disk posts and failure of an HPT disk post. This proposed AD would
require the removal and replacement of the affected HPT disk before
reaching its new life limit. The FAA is proposing this AD to address
the unsafe condition on these products.
DATES: The FAA must receive comments on this proposed AD by August 9,
2021.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
<bullet> Federal eRulemaking Portal: Go to <a href="https://www.regulations.gov">https://www.regulations.gov</a>. Follow the instructions for submitting comments.
<bullet> Fax: (202) 493-2251.
<bullet> 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.
<bullet> 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 Williams
International Co., L.L.C., Product Support, 2000 Centerpoint Pkwy.,
Pontiac, MI 48341; phone: (800) 859-3544; website: <a href="http://www.williams-int.com/product-support">http://www.williams-int.com/product-support</a>. You may view this service information at the
Chicago ACO Branch, 2300 East Devon Avenue, Des Plaines, IL 60018. For
information on the availability of this material at the FAA, call (781)
238-7759.
Examining the AD Docket
You may examine the AD docket at <a href="https://www.regulations.gov">https://www.regulations.gov</a> 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 NPRM, 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 Branch, FAA, 2300 East Devon Avenue, Des Plaines, IL 60018;
phone: (847) 294-7870; fax: (847) 294-7834; email: <a href="/cdn-cgi/l/email-protection#d3b8aabfb6fdb1a6a0bb93b5b2b2fdb4bca5"><span class="__cf_email__" data-cfemail="8fe4f6e3eaa1edfafce7cfe9eeeea1e8e0f9">[email protected]</span></a>.
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 amend
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
<a href="https://www.regulations.gov">https://www.regulations.gov</a>, including any personal information you
provide. The agency will also post a report summarizing each
substantive verbal contact received about this NPRM.
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 Kyle
Bush, Aviation Safety Engineer, Chicago ACO Branch, 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 received a report that Williams discovered cracks in one
HPT disk post during a scheduled inspection of an FJ44-2A model
turbofan engine. An operator also discovered that one HPT disk post
failed, while the engine was in service, resulting in the release of an
HPT blade.
Williams initiated an investigation to understand the root cause of
the cracks and to determine the necessary corrective action. Williams
found that, between August 2018 and July 2019, nine FJ44-2A HPT disks
were rejected during inspection after discovery of cracks in the HPT
disk post. As part of its investigation, Williams conducted several
tests and analysis to determine the failure mechanism. Engine tests
confirmed that FJ44-2A and FJ44-2C model turbofan engines operate at a
higher temperature than most recently certified engines. Metallurgical
evaluation showed cracking is inter-granular with oxidation attack near
and around the crack, with no fatigue striations. Metallurgical
evaluation and comparison of HPT disk, part number (P/N) 67093,
installed on both FJ44-2A and FJ44-3A model turbofan engines, showed
cracking of the HPT disk.
As a result of this investigation, Williams determined the root
cause of this cracking was due to higher temperatures and a difference
in manufacturing processes (electrical discharge machining vs.
broaching). Williams determined that these cracks have only occurred on
HPT disks with P/N 67093. Williams subsequently issued service
information to instruct operators to remove the HPT disk, P/N 67093.
This condition, if not addressed, could result in failure of the
engine, in-flight shutdown of the engine, and loss of control of the
aircraft.
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.
[[Page 33580]]
Related Service Information Under 1 CFR Part 51
The FAA reviewed Williams International Service Bulletin (SB) WISB-
72-1032, dated March 23, 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
1, dated June 10, 2020. Williams International SB WISB-72-1034
describes procedures for re-identifying the HPT rotor assembly and HPT
disk.
Proposed AD Requirements in This NPRM
This proposed AD would 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.
Differences Between This Proposed AD and the Service Information
The Accomplishment Instructions, paragraph 2.D., of Williams
International SB WISB-72-1032, dated March 23, 2020, instruct operators
of FJ44-2A and FJ44-2C model turbofan engines to replace or rework the
HPT combustor/fuel slinger module on FJ44-2A and FJ44-2C model turbofan
engines, while this proposed AD does not. Replacement or rework of the
HPT combustor/fuel slinger module is not necessary to resolve the
unsafe condition in this proposed AD and is therefore not proposed by
this AD.
The Accomplishment Instructions, paragraphs 2.C. and E. and 3.C.
and D., of Williams International SB WISB-72-1032, dated March 23,
2020, specify procedures for removing and replacing the HP turbine
rotor assembly containing HPT disk, P/N 67093, whereas this proposed AD
mandates 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 213 engines installed on airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed
AD:
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Remove and replace the HPT disk....... 33 work-hours x $85 per $16,694 $19,499 $4,153,287
hour = $2,805.
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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. 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 August 9, 2021.
(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 a serial number identified in paragraph 1.A., Effectivity, of
Williams International Service Bulletin WISB-72-1032, dated March
23, 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.
[[Page 33581]]
(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 release of an HPT
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 uncontained 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] TP25JN21.009
(h) Definition
For the purpose of this AD, a part eligible for installation is
an HPT disk with a P/N other than 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 Related Information.
(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 Branch, FAA, 2300 East Devon
Avenue, Des Plaines, IL 60018; phone: (847) 294-7870; fax: (847)
294-7834; email: <a href="/cdn-cgi/l/email-protection#6b0012070e45091e18032b0d0a0a450c041d"><span class="__cf_email__" data-cfemail="8ee5f7e2eba0ecfbfde6cee8efefa0e9e1f8">[email protected]</span></a>.
(2) For service information identified in this AD, contact
Williams International Co., L.L.C., Product Support, 2000
Centerpoint Pkwy, Pontiac, MI 48341; phone: (800) 859-3544; website:
<a href="http://www.williams-int.com/product-support">http://www.williams-int.com/product-support</a>. 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 (781) 238-7759.
Issued on June 21, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2021-13516 Filed 6-24-21; 8:45 am]
BILLING CODE 4910-13-P
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