AD 56-20-03
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Scotts-Bell 47 Inc | 47B | Airworthiness Directives; Bell Model 47B, 47B3, 47D, 47D1, 47G, 47G2 and 47H1 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47B3 | Airworthiness Directives; Bell Model 47B, 47B3, 47D, 47D1, 47G, 47G2 and 47H1 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47D | Airworthiness Directives; Bell Model 47B, 47B3, 47D, 47D1, 47G, 47G2 and 47H1 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47D1 | Airworthiness Directives; Bell Model 47B, 47B3, 47D, 47D1, 47G, 47G2 and 47H1 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G | Airworthiness Directives; Bell Model 47B, 47B3, 47D, 47D1, 47G, 47G2 and 47H1 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47G-2 | Airworthiness Directives; Bell Model 47B, 47B3, 47D, 47D1, 47G, 47G2 and 47H1 Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47H-1 | Airworthiness Directives; Bell Model 47B, 47B3, 47D, 47D1, 47G, 47G2 and 47H1 Helicopters |
Unsafe Condition
Failure of the tail rotor hub retention bolts P/N 47-641-052-1 has occurred in service.
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Required Actions
Remove the two tail rotor retention bolts and replace them with new retention bolts of the same part number, establishing a service life limit of 300 hours.
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Compliance Time
as soon as possible but not later than October 20, 1956
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Affected Aircraft
Bell Model 47B, 47B3, 47D, 47D1, 47G, 47G2 and 47H1 Helicopters
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Federal Register Abstract
Tail Rotor Hub Bolts
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_56-20-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 56-20-03 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Bell Model 47B, 47B3, 47D, 47D1, 47G, 47G2 and 47H1 Helicopters Subject: Tail Rotor Hub Bolts Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Scotts-Bell 47 Inc Model: 47B | 47B3 | 47D | 47D1 | 47G | 47G-2 | 47H-1 Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 56-20-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 56-20-03 SUBJECT HEADING: Airworthiness Directives; Bell Model 47B, 47B3, 47D, 47D1, 47G, 47G2 and 47H1 Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 56-20-03 BELL: Applies to All Models 47B, 47B3, 47D, 47D1, 47G, 47G2 and 47H1. Compliance required as soon as possible but not later than October 20, 1956. Failure of the tail rotor hub retention bolts P/N 47-641-052-1 has occurred in service. The probable cause of the bolt failures experienced to date has not been determined and this problem is currently being investigated. At the conclusion of this investigation Bell anticipates supplying a newly designed hub retention bolt as a replacement for the present bolts. In the interim it is mandatory that a service life of 300 hours be established for the subject bolt. At this time it is necessary to remove the two tail rotor retention bolts and replace them with new retention bolts of the same part number. (Bell Mandatory Service Bulletin No. 112 dated August 8, 1956, covers this same subject.) FOOTER:
Document Text
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AD Final Rules - DRS_56-20-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 56-20-03 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Bell Model 47B, 47B3, 47D, 47D1, 47G, 47G2 and 47H1 Helicopters Subject: Tail Rotor Hub Bolts Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Scotts-Bell 47 Inc Model: 47B | 47B3 | 47D | 47D1 | 47G | 47G-2 | 47H-1 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: 56-20-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 56-20-03 SUBJECT HEADING: Airworthiness Directives; Bell Model 47B, 47B3, 47D, 47D1, 47G, 47G2 and 47H1 Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 56-20-03 BELL: Applies to All Models 47B, 47B3, 47D, 47D1, 47G, 47G2 and 47H1. Compliance required as soon as possible but not later than October 20, 1956. Failure of the tail rotor hub retention bolts P/N 47-641-052-1 has occurred in service. The probable cause of the bolt failures experienced to date has not been determined and this problem is currently being investigated. At the conclusion of this investigation Bell anticipates supplying a newly designed hub retention bolt as a replacement for the present bolts. In the interim it is mandatory that a service life of 300 hours be established for the subject bolt. At this time it is necessary to remove the two tail rotor retention bolts and replace them with new retention bolts of the same part number. (Bell Mandatory Service Bulletin No. 112 dated August 8, 1956, covers this same subject.) FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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