AD 56-05-01
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
Tail rotor extension drive shafts P/N 47-644-172-3 were bored too deep, resulting in a weakened wall section due to manufacturing error.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect tail rotor extension drive shafts using X-ray or the method described in Bell Service Bulletin No. 106. Replace any shafts found to be non-compliant.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
March 1, 1956
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Bell Model 47 Helicopters: Model 47D1 Serial Number 477 and subsequent, Model 47G Serial Numbers 667 through 692, 694 through 1511, Model 47G2 Serial Numbers 1342 through 1418, Model 47H1 Serial Numbers 1347, 1349 through 1356, 1358, and 1360, all models modified to include P/N 47-644-172-3 tail rotor extension drive shafts, and all such shafts in stock.
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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