AD 77-24-03

final rule
Data completeness: 70%

Airworthiness Directives; Hiller Models UH-12C, UH-12D, UH-12E, UH-12L, UH-12E-L, and UH-12L4 Helicopters

AD Number
77-24-03
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Hiller Aviation | Siam Hiller Holdings, Inc. UH-12C Airworthiness Directives; Hiller Models UH-12C, UH-12D, UH-12E, UH-12L, UH-12E-L, and UH-12L4 Helicopters
aircraft Hiller Aviation | Siam Hiller Holdings, Inc. UH-12D Airworthiness Directives; Hiller Models UH-12C, UH-12D, UH-12E, UH-12L, UH-12E-L, and UH-12L4 Helicopters
aircraft Hiller Aviation | Siam Hiller Holdings, Inc. UH-12L Airworthiness Directives; Hiller Models UH-12C, UH-12D, UH-12E, UH-12L, UH-12E-L, and UH-12L4 Helicopters
aircraft Hiller Aviation | Siam Hiller Holdings, Inc. UH-12L4 Airworthiness Directives; Hiller Models UH-12C, UH-12D, UH-12E, UH-12L, UH-12E-L, and UH-12L4 Helicopters
aircraft Hiller Aviation | Siam Hiller Holdings, Inc. UH-12E Airworthiness Directives; Hiller Models UH-12C, UH-12D, UH-12E, UH-12L, UH-12E-L, and UH-12L4 Helicopters
aircraft Hiller Aviation | Siam Hiller Holdings, Inc. UH-12E-L Airworthiness Directives; Hiller Models UH-12C, UH-12D, UH-12E, UH-12L, UH-12E-L, and UH-12L4 Helicopters

Unsafe Condition

Hazardous engine power loss from inadvertent shutoff of the fuel control valve.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Install a guard on the fuel shutoff valve handle in accordance with Hiller Service Bulletin No. 72-1 dated June 17, 1977, or later FAA approved revision. Equivalent methods may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

within the next 100 hours time in service after the effective date of this AD

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Hiller Models UH-12C, UH-12D, UH-12E, UH-12L, UH-12E-L, and UH-12L4 helicopters with control levers P/N 72229 or 72210, all serial numbers up to No. 5024.

AI-generated summary from the source AD text. Verify against the official source before acting.

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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