AD 55-16-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Scotts-Bell 47 Inc | 47 | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47B | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47B3 | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47D | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47D1 | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47E | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-2 | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-2A | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-2A-1 | Airworthiness Directives; Bell Model 47 Helicopters |
Unsafe Condition
Failure of the tail rotor hubs P/N 47-641-025-1 and 47-641-057-1 due to imperfections such as corrosion, tool marks, scratches, and pitting in the fillet area causing stress concentrations and hub spindle failure.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the inboard fillet area on both spindles of the hub using a 10-power magnifying glass for accurate radius and smooth machine finish free of corrosion, pitting, and copper plating. Replace hubs not meeting requirements.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
prior to next flight
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
All Model 47 Helicopters with 47-641-025-1 or 47-641-057-1 Tail Rotor Hubs and all spares.
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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