AD 81-04-01

final rule
Data completeness: 70%

Airworthiness Directives; HILLER AIRCRAFT Models UH-12D, UH-12E, OH-23G, UH-12L Helicopters

AD Number
81-04-01
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-12D Airworthiness Directives; HILLER AIRCRAFT Models UH-12D, UH-12E, OH-23G, UH-12L Helicopters
aircraft Hiller Aviation | Siam Hiller Holdings, Inc. UH-12L Airworthiness Directives; HILLER AIRCRAFT Models UH-12D, UH-12E, OH-23G, UH-12L Helicopters
aircraft Hiller Aviation | Siam Hiller Holdings, Inc. UH-12E Airworthiness Directives; HILLER AIRCRAFT Models UH-12D, UH-12E, OH-23G, UH-12L Helicopters

Unsafe Condition

Rudder balance cables (P/N HS 1053-2) may fray and break due to non-conformance with the type design requiring 7 x 19 cable.

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

Required Actions

Perform a one-time visual inspection of the rudder balance cable assembly per Hiller Service Bulletin No. 32-2 Part II, Subparts A and B. Remove non-conforming rudder cable assemblies (P/N HS 1053-2) from service. Use special flight permits under FAR 21.197/21.199 to relocate aircraft for AD compliance.

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

Compliance Time

within ten (10) calendar days from the effective date of this AD

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

Affected Aircraft

Hiller Aircraft Models UH-12D, UH-12E, OH-23G, UH-12L, and all models converted to turbine power via STC 177WE or STC 178WE

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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