Proposed Rule2025-00588
Airworthiness Directives; Siam Hiller Holdings, Inc, Helicopters
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
January 14, 2025
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for Siam Hiller Holdings, Inc. (Siam Hiller), Model UH-12E (Army OH-23G and H-23F) and UH-12E-L helicopters. This proposed AD was prompted by reports of cracks found in a main rotor (M/R) transmission drive shaft (drive shaft). This proposed AD would require inspecting certain M/R drive shafts for a crack, prohibit installing certain M/R drive shafts unless the inspection is done, and prohibit using certain paint removers. The FAA is proposing this AD to address the unsafe condition on these products.
Full Text
<html>
<head>
<title>Federal Register, Volume 90 Issue 8 (Tuesday, January 14, 2025)</title>
</head>
<body><pre>
[Federal Register Volume 90, Number 8 (Tuesday, January 14, 2025)]
[Proposed Rules]
[Pages 3046-3048]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-00588]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-2555; Project Identifier AD-2024-00214-R]
RIN 2120-AA64
Airworthiness Directives; Siam Hiller Holdings, Inc, Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for Siam Hiller Holdings, Inc. (Siam Hiller), Model UH-12E (Army OH-23G
and H-23F) and UH-12E-L helicopters. This proposed AD was prompted by
reports of cracks found in a main rotor (M/R) transmission drive shaft
(drive shaft). This proposed AD would require inspecting certain M/R
drive shafts for a crack, prohibit installing certain M/R drive shafts
unless the inspection is done, and prohibit using certain paint
removers. 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 February
28, 2025.
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="http://regulations.gov">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.
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2024-2555; 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.
Other Related Material: For Hiller Aircraft Corporation material
identified in this proposed AD, contact Hiller Aircraft Corporation,
925 M Street, Firebaugh, CA 93622; phone: (559) 659-5959; or website:
<a href="http://hilleraircraftcorporation.com/">hilleraircraftcorporation.com/</a>.
[[Page 3047]]
FOR FURTHER INFORMATION CONTACT: Calvin L. Hang, Aviation Safety
Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone:
(562) 627-5254; email: <a href="/cdn-cgi/l/email-protection#ca89aba6bca3a4e486e482aba4ad8aacababe4ada5bc"><span class="__cf_email__" data-cfemail="1b587a776d7275355735537a757c5b7d7a7a357c746d">[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 the ADDRESSES section. Include ``Docket No. FAA-2024-2555;
Project Identifier AD-2024-00214-R'' 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 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
<a href="http://regulations.gov">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
Calvin L. Hang, Aviation Safety Engineer, FAA, 3960 Paramount
Boulevard, Lakewood, CA 90712; phone: (562) 627-5254; email:
<a href="/cdn-cgi/l/email-protection#cc8fada0baa5a2e280e284ada2ab8caaadade2aba3ba"><span class="__cf_email__" data-cfemail="e5a68489938c8bcba9cbad848b82a5838484cb828a93">[email protected]</span></a>. 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 of two cracks in an M/R drive shaft that
were found during an inspection involving a Siam Hiller Model UH-12E
helicopter. These cracks resulted from hydrogen embrittlement, possibly
due to improper baking after the electroplating process, and certain
paint strippers exploiting galvanic potential between the steel and
cadmium. Since the affected part may also be installed on Model UH-12E-
L helicopters, this model helicopter is also affected by this unsafe
condition.
Accordingly, this proposed AD would require inspecting certain M/R
drive shafts for a crack, prohibit installing certain M/R drive shafts
unless the inspection is done, and prohibit using certain paint
removers. This condition, if not addressed, could result in could
result in loss of the M/R drive shaft and subsequent loss of control of
the helicopter.
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.
Other Related Material
The FAA reviewed Hiller Aircraft Corporation UH-12E Series
Helicopters, Main Rotor Transmission Assembly, Overhaul Manual 63-20,
dated June 01, 2015. This material specifies overhaul procedures for
the M/R transmission assemblies.
Proposed AD Requirements in This NPRM
This proposed AD would require, with the M/R drive shaft removed,
removing the coatings from all surfaces of the M/R drive shaft by using
certain paint strippers, hydrogen embrittlement relief baking the M/R
drive shaft, and performing a magnetic particle inspection of the M/R
drive shaft for a crack. Depending on the results of the magnetic
particle inspection, this proposed AD would require removing the M/R
drive shaft from service and installing an airworthy part. This
proposed AD would also prohibit installing an affected M/R drive shaft
on any helicopter unless the actions required by this proposed AD have
been accomplished and prohibit using certain paint removers on the M/R
drive shaft.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 110 helicopters of U.S. registry. Labor costs are estimated at
$85 per work-hour. Based on these numbers, the FAA estimates the
following costs to comply with this proposed AD.
Removing the coatings, hydrogen embrittlement relief baking, and
magnetic particle inspecting the M/R drive shaft would take 5 work-
hours and parts would cost $500 for an estimated cost of $925 per
helicopter and $101,750 for the U.S. fleet. If required, replacing the
M/R drive shaft would take 5 work-hours and parts would cost $15,000
for an estimated cost of $15,425 per helicopter.
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.
[[Page 3048]]
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:
Siam Hiller Holdings, Inc.: Docket No. FAA-2024-2555; Project
Identifier AD-2024-00214-R.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by February 28, 2025.
(b) Affected ADs
None.
(c) Applicability
This AD Applies to Siam Hiller Holdings, Inc., Model UH-12E
(Army OH-23G and H-23F) and UH-12E-L helicopters, certificated in
any category, with a main rotor (M/R) transmission drive shaft
(drive shaft) having part number (P/N) 23600, installed.
Note 1 to paragraph (c): Hiller Aircraft Corporation material
refers to an M/R drive shaft as a transmission M/R mast and M/R
drive shaft, interchangeably.
(d) Subject
Joint Aircraft System Component (JASC) Code 6230, Main Rotor
Mast/Swashplate.
(e) Unsafe Condition
This AD was prompted by reports of cracks in the M/R drive
shaft. The FAA is issuing this AD to address non-conforming parts
and the use of improper paint stripper; and detect cracking of the
M/R drive shaft. The unsafe condition, if not addressed, could
result in separation of the M/R drive shaft and M/R blades from the
helicopter and subsequent loss of control of the helicopter.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
For an M/R drive shaft that has accumulated 1,200 or more total
hours time-in-service (TIS) or 4 or more years since new, or at the
next overhaul of the M/R transmission assembly after the effective
date of this AD, whichever occurs first, with the M/R drive shaft
removed, inspect the M/R drive shaft by accomplishing the actions
required by paragraphs (g)(1) through (3) of this AD.
(1) Remove all coatings from all surfaces of the M/R drive shaft
by using paint stripper TT-R-248B or TT-R-2918A Type I.
(2) Hydrogen embrittlement relief bake the M/R drive shaft for
24 hours minimum at 375 [deg]F <plus-minus> 25 [deg]F.
(3) Magnetic particle inspect all surfaces of the M/R drive
shaft for a crack. This magnetic particle inspection must be
accomplished by a Level II or Level III inspector certified in the
FAA-acceptable standards for nondestructive inspection personnel. If
there is a crack, before further flight, remove the M/R drive shaft
from service and install an airworthy M/R drive shaft.
Note 2 to paragraph (g)(3): Advisory Circular 65-31B contains
examples of FAA-acceptable Level II and Level III qualification
standards criteria for inspection personnel doing nondestructive
test inspections.
Note 3 to paragraph (g): Hiller Aircraft Corporation Main Rotor
Transmission Assembly Overhaul Manual, Manual 63-20, for UH-12E
Series Helicopters, accepted May 6, 2015, contains additional
information pertaining to inspecting the M/R drive shaft.
(h) Parts Installation Limitations
(1) As of the effective date of this AD, do not install an M/R
drive shaft having P/N 23600 on any helicopter unless the actions
required by paragraphs (g)(1) through (3) of this AD have been
accomplished.
(2) As of the effective date of this AD, do not use any other
paint stripper other than TT-R-248B or TT-R-2918A Type I to remove
coatings from all areas of the M/R drive shaft.
(i) Alternative Methods of Compliance (AMOCs)
(1) The Manager, West Certification 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 West Certification Branch, send it to
the attention of the person identified in paragraph (j)(1) of this
AD. Information may be emailed to: <a href="/cdn-cgi/l/email-protection#b5f4f8faf6f5d3d4d49bd2dac3"><span class="__cf_email__" data-cfemail="4f0e02000c0f292e2e61282039">[email protected]</span></a>.
(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) Additional Information
(1) For more information about this AD, contact Calvin L. Hang,
Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood,
CA 90712; phone: (562) 627-5254; email: <a href="/cdn-cgi/l/email-protection#3675575a405f58187a187e5758517650575718515940"><span class="__cf_email__" data-cfemail="1754767b617e79395b395f7679705771767639707861">[email protected]</span></a>.
(2) For Hiller Aircraft Corporation material identified in this
AD that is not incorporated by reference, contact Hiller Aircraft
Corporation, 925 M Street, Firebaugh, CA 93622; phone: (559) 659-
5959; or website: <a href="http://hilleraircraftcorporation.com/">hilleraircraftcorporation.com/</a>.
(3) For advisory circular material identified in this AD that is
not incorporated by reference, go to <a href="http://faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/1023552">faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/1023552</a>.
(k) Material Incorporated by Reference
None.
Issued on December 9, 2024.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2025-00588 Filed 1-13-25; 8:45 am]
BILLING CODE 4910-13-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on January 14, 2025.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.