AD 52-29-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Hiller Aviation | UH-12 | Airworthiness Directives; Hiller Models UH-12,-12A,-12B Helicopters |
| aircraft | Hiller Aviation | UH-12A | Airworthiness Directives; Hiller Models UH-12,-12A,-12B Helicopters |
| aircraft | Hiller Aviation | UH-12B | Airworthiness Directives; Hiller Models UH-12,-12A,-12B Helicopters |
Unsafe Condition
Separation of the components of the forward tail rotor drive slip joint assembly, and eventual power loss to the tail rotor, may result from a severely hard landing or misalignment of the yoke and cam followers of the 'T' fitting following tail rotor drive system maintenance work.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Scribe marks on the yoke fingers and bearing cap of the cam follower for alignment inspection. Ensure the line on the bearing cap lies within the scribed marks on the yoke. Correct misalignment by referring to the Maintenance Manual and specified part numbers.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
by February 1, 1953, and thereafter following any unusually hard landing, or following any maintenance work requiring loosening of the cardan joint assembly attachment to fuselage, or removal of the forward tail rotor drive tube or tail boom assembly
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Hiller Models UH-12, -12A, -12B Helicopters
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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