AD 78-22-08
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Hiller Aviation | Siam Hiller Holdings, Inc. | UH-12D | Airworthiness Directives; Hiller Models UH-12D, UH-12E, and UH-12E 4-Place Helicopters |
| aircraft | Hiller Aviation | Siam Hiller Holdings, Inc. | UH-12E | Airworthiness Directives; Hiller Models UH-12D, UH-12E, and UH-12E 4-Place Helicopters |
Unsafe Condition
Loss of flight control or engine control
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Required Actions
Modify the integrated collective and N2 engine control system per Soloy Conversions, Ltd. Service Bulletin 06-560 or approved revision. Remove specified N1 and N2 engine control cables and install replacement cables as per the same bulletin. Equivalent modifications may be approved by the FAA.
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Compliance Time
on or before January 1, 1979
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Affected Aircraft
Hiller Models UH-12D, UH-12E, and UH-12E 4-Place Helicopters converted to turbine power under Soloy Conversions STC Nos. SH177WE and SH178WE
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Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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