FAA · Airworthiness Directive
Airworthiness Directives; Siam Hiller Holdings, Inc, Helicopters
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.
Applicability
Aircraft makes and models this AD applies to, sorted by US-registered fleet size.
Federal Register text
Verbatim from the Federal Register publication — required actions, compliance times, parts/serial numbers, and methods of compliance. The Federal Register is the legally binding document; this rendering is for readability. Cite: 90 FR 3046.
[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 [www.gpo.gov] [FR Doc No: 2025-00588]
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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).
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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: Federal eRulemaking Portal: Go to 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. AD Docket: You may examine the AD docket at regulations.gov 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: hilleraircraftcorporation.com/.
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FOR FURTHER INFORMATION CONTACT: Calvin L. Hang, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: (562) 627-5254; email: [email protected].