AD 74-25-10
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Bell Helicopter Textron Canada Limited | 206A | Airworthiness Directives; Bell Model 206A and 206B Helicopters |
| aircraft | Bell Helicopter Textron Canada Limited | 206B | Airworthiness Directives; Bell Model 206A and 206B Helicopters |
Unsafe Condition
Failure of the rotor brake disc which could cause serious damage to critical components of the helicopter.
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Required Actions
Remove the engine to transmission driveshaft and aft coupling, remove the Rotor Brake Disc Assembly P/N 4000071 or 4000071-1, bolts, and gasket, reinstall the coupling and driveshaft, disable the brake by removing the P/N 156F538-4S-0061 hose assembly and capping the AN833-4C elbows with AN929-4J caps or equivalent, and follow Bell Service Bulletin 206-50-74-1 or FAA/DER approved revisions.
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Compliance Time
within the next ten hours' time in service after the effective date of this airworthiness directive unless already accomplished
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Affected Aircraft
Bell Helicopter Textron Canada Limited Model 206A and 206B helicopters equipped with Rotor Brake Kit P/N 206-706-032-1
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Federal Register Abstract
Rotor Brake Disc
Applicability Source Text
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AD Final Rules - DRS_74-25-10.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 74-25-10 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Bell Model 206A and 206B Helicopters Subject: Rotor Brake Disc Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 12/16/1974 Make: Bell Helicopter Textron Canada Limited Model: 206A | 206B Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 74-25-10 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2039 AD NUMBER: 74-25-10 SUBJECT HEADING: Airworthiness Directives; Bell Model 206A and 206B Helicopters ACTION: SUMMARY: DATES: Effective December 16, 1974. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 74-25-10 BELL: Amendment 39-2039. Applies to Model 206A and 206B helicopters certificated in all categories and equipped with Rotor Brake Kit, P/N 206-706-032-1. Compliance required within the next ten hours' time in service after the effective date of this airworthiness directive unless already accomplished. To prevent failure of the rotor brake disc which could cause serious damage to critical components of the helicopter, accomplish the following: a. Remove the engine to transmission driveshaft and aft coupling. (Refer to Section VI of the Maintenance and Overhaul Manual.) b. Remove the Rotor Brake Disc Assembly P/N 4000071 or 4000071-1, attachment bolts and gasket from the coupling and discard. c. Reinstall the coupling and driveshaft as described in the Maintenance and Overhaul Manual. d. Disable the brake by removing the P/N 156F538-4S-0061 hose assembly between the rotor brake and firewall and capping the AN833-4C elbows with AN929-4J caps or equivalent. e. Bell Service Bulletin No. 206-50-74-1, Revision A, dated October 29, 1974 or later FAA/DER Approved Revision, includes equivalent instructions for these procedures and lists alternate FAA approved rotor brake configurations. f. Equivalent methods of compliance with this Airworthiness Directive must be approved by the Chief, Engineering and Manufacturing Branch, Flight Standards Division, Southwest Region, Federal Aviation Administration. This amendment becomes effective December 16, 1974. FOOTER:
Document Text
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AD Final Rules - DRS_74-25-10.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 74-25-10 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Bell Model 206A and 206B Helicopters Subject: Rotor Brake Disc Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 12/16/1974 Make: Bell Helicopter Textron Canada Limited Model: 206A | 206B 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: 74-25-10 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2039 AD NUMBER: 74-25-10 SUBJECT HEADING: Airworthiness Directives; Bell Model 206A and 206B Helicopters ACTION: SUMMARY: DATES: Effective December 16, 1974. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 74-25-10 BELL: Amendment 39-2039. Applies to Model 206A and 206B helicopters certificated in all categories and equipped with Rotor Brake Kit, P/N 206-706-032-1. Compliance required within the next ten hours' time in service after the effective date of this airworthiness directive unless already accomplished. To prevent failure of the rotor brake disc which could cause serious damage to critical components of the helicopter, accomplish the following: a. Remove the engine to transmission driveshaft and aft coupling. (Refer to Section VI of the Maintenance and Overhaul Manual.) b. Remove the Rotor Brake Disc Assembly P/N 4000071 or 4000071-1, attachment bolts and gasket from the coupling and discard. c. Reinstall the coupling and driveshaft as described in the Maintenance and Overhaul Manual. d. Disable the brake by removing the P/N 156F538-4S-0061 hose assembly between the rotor brake and firewall and capping the AN833-4C elbows with AN929-4J caps or equivalent. e. Bell Service Bulletin No. 206-50-74-1, Revision A, dated October 29, 1974 or later FAA/DER Approved Revision, includes equivalent instructions for these procedures and lists alternate FAA approved rotor brake configurations. f. Equivalent methods of compliance with this Airworthiness Directive must be approved by the Chief, Engineering and Manufacturing Branch, Flight Standards Division, Southwest Region, Federal Aviation Administration. This amendment becomes effective December 16, 1974. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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