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 |
| aircraft | Scotts-Bell 47 Inc | 47G-3 | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-3B | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-3B-1 | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-3B-2 | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-3B-2A | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-4 | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-4A | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-5 | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-5A | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47H-1 | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47J | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47J-2 | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47J-2A | Airworthiness Directives; Bell Model 47 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47K | 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.
Federal Register Abstract
Tail Rotor Drive Shafts
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_56-05-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 56-05-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Bell Model 47 Helicopters Subject: Tail Rotor Drive Shafts Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Scotts-Bell 47 Inc Model: 47 | 47B | 47B3 | 47D | 47D1 | 47E | 47G | 47G-2 | 47G-2A | 47G-2A-1 | 47G-3 | 47G-3B | 47G-3B-1 | 4...Show more Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 56-05-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 56-05-01 SUBJECT HEADING: Airworthiness Directives; Bell Model 47 Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 56-05-01 BELL: Applies to 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 Model 47 Modified to Include 47-644-172-3 Tail Rotor Extension Drive Shaft and All 47-644-172-3 Shafts in Stock. Compliance required by March 1, 1956. As a result of manufacturing error some Bell Model 47 tail rotor extension drive shafts P/N 47-644-172-3 were bored too deep resulting in a weakened wall section. Bell has issued Service Bulletin No. 106 requiring an immediate mandatory inspection by X-ray or by method described in the Service Bulletin. This supersedes telegraph AD of February 3, 1956. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_56-05-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 56-05-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Bell Model 47 Helicopters Subject: Tail Rotor Drive Shafts Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Scotts-Bell 47 Inc Model: 47 | 47B | 47B3 | 47D | 47D1 | 47E | 47G | 47G-2 | 47G-2A | 47G-2A-1 | 47G-3 | 47G-3B | 47G-3B-1 | 4...Show more Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 56-05-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 56-05-01 SUBJECT HEADING: Airworthiness Directives; Bell Model 47 Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 56-05-01 BELL: Applies to 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 Model 47 Modified to Include 47-644-172-3 Tail Rotor Extension Drive Shaft and All 47-644-172-3 Shafts in Stock. Compliance required by March 1, 1956. As a result of manufacturing error some Bell Model 47 tail rotor extension drive shafts P/N 47-644-172-3 were bored too deep resulting in a weakened wall section. Bell has issued Service Bulletin No. 106 requiring an immediate mandatory inspection by X-ray or by method described in the Service Bulletin. This supersedes telegraph AD of February 3, 1956. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.
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