AD 48-12-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Scotts-Bell 47 Inc | 47B | Airworthiness Directives; Bell Model 47B Series and 47D Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47B3 | Airworthiness Directives; Bell Model 47B Series and 47D Helicopters |
| aircraft | Scotts-Bell 47 Inc | 47D | Airworthiness Directives; Bell Model 47B Series and 47D Helicopters |
Unsafe Condition
The dural shear screws in the transmission spider assembly may fail due to insufficient strength, leading to potential transmission failure.
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Required Actions
Replace the dural shear screws in the transmission spider assembly with steel shear screws (P/N 47-620-485-1) at the next 100-hour teardown inspection if less than 600 hours have been accumulated. If over 600 hours have been accumulated, the replacement must be accomplished immediately.
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Compliance Time
next 100-hour teardown inspection if less than 600 hours have been accumulated. If over 600 hours have been accumulated, this change must be accomplished immediately
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Affected Aircraft
Scotts-Bell 47 Inc Models 47B Series, 47B3, and 47D helicopters
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Federal Register Abstract
Shear Screw Replacement
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_48-12-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 48-12-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Bell Model 47B Series and 47D Helicopters Subject: Shear Screw Replacement Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Scotts-Bell 47 Inc Model: 47B | 47B3 | 47D Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 48-12-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 48-12-05 SUBJECT HEADING: Airworthiness Directives; Bell Model 47B Series and 47D Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 48-12-05 BELL: Applies to Models 47B Series and 47D. Compliance required at next 100-hour teardown inspection if less than 600 hours have been accumulated. (If over 600 hours have been accumulated, this change must be accomplished immediately.) Replace the dural shear screws in the transmission spider assembly with steel shear screws (P/N 47-620-485-1). (Bell Service Bulletin No. 47C66, revised February 10, 1948, also covers this same subject.) FOOTER:
Document Text
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AD Final Rules - DRS_48-12-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 48-12-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Bell Model 47B Series and 47D Helicopters Subject: Shear Screw Replacement Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Scotts-Bell 47 Inc Model: 47B | 47B3 | 47D 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: 48-12-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 48-12-05 SUBJECT HEADING: Airworthiness Directives; Bell Model 47B Series and 47D Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 48-12-05 BELL: Applies to Models 47B Series and 47D. Compliance required at next 100-hour teardown inspection if less than 600 hours have been accumulated. (If over 600 hours have been accumulated, this change must be accomplished immediately.) Replace the dural shear screws in the transmission spider assembly with steel shear screws (P/N 47-620-485-1). (Bell Service Bulletin No. 47C66, revised February 10, 1948, also covers this same subject.) FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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