AD 61-04-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Brantly International, Inc. | B-2 | Airworthiness Directives; BRANTLY Models B-2 Helicopters |
| aircraft | Brantly International, Inc. | B-2A | Airworthiness Directives; BRANTLY Models B-2 Helicopters |
| aircraft | Brantly International, Inc. | B-2B | Airworthiness Directives; BRANTLY Models B-2 Helicopters |
Unsafe Condition
Centrifugal clutch failure to release at engine shutdown can shear AN 4-10A bolts transmitting torque between the B2-8-14 clutch disc assembly, fabric coupling, and free-wheeling clutch housing lugs.
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Required Actions
Inspect all 6 AN 4-10A bolts securing the fabric coupling within 10 hours of flight time post-effective date. Replace any sheared bolts before further operation. Install a placard near the fuel mixture control to remind operators to manually check clutch freedom before each engine start.
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Compliance Time
within the next 10 hours of flight time after the effective date of this directive
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Affected Aircraft
Brantly International, Inc. Models B-2, B-2A, B-2B helicopters; all serial numbers
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Federal Register Abstract
Clutch Bolts
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_61-04-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 61-04-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; BRANTLY Models B-2 Helicopters Subject: Clutch Bolts Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 02/22/1961 Make: Brantly International, Inc. Model: B-2 | B-2A | B-2B Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 61-04-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 61-04-01 SUBJECT HEADING: Airworthiness Directives; BRANTLY Models B-2 Helicopters ACTION: SUMMARY: DATES: Effective February 22, 1961. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 61-04-01 BRANTLY: Amdt. 252 Part 507 Federal Register February 10, 1961. Applies to All B-2 Helicopters. Compliance required as indicated. Instances have occurred wherein the centrifugal clutch has failed to release at engine shutdown and subsequent restarting has sheared the bolts which transmit torque from the B2-8-14 clutch disc assembly into the fabric coupling and from the fabric coupling into the lugs of the free-wheeling clutch housing. To preclude recurrence of this condition the following must be accomplished: (a) Within the next 10 hours of flight time after the effective date of this directive, inspect all 6 of the AN 4-10A bolts which secure the fabric coupling to the B2-8-14 clutch disc assembly and to the free-wheeling clutch housing for shear failure. This inspection is to be accomplished by inserting an appropriately sized wrench through the lubrication access hole in the B2-7-17 clutch dust cover and checking each bolt for snugness. Any sheared bolts must be replaced prior to further operation. (b) Within the next 10 hours of flight time after the effective date of this directive a placard shall be installed immediately aft or incorporated with the operating limitations placard located between the fuel mixture control and the carburetor heat control levers to read: "PRIOR TO EACH ENGINE START, TURN ROTOR BACKWARD BY HAND THROUGH 30 DEGREES MINIMUM TO CHECK CLUTCH FREEDOM." The purpose of this placard is to insure that these coupling bolts are not subjected to damage resulting from failure of the clutch to release. (Brantly Service Bulletin No. 6 covers this same subject.) This directive effective February 22, 1961. FOOTER:
Document Text
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AD Final Rules - DRS_61-04-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 61-04-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; BRANTLY Models B-2 Helicopters Subject: Clutch Bolts Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 02/22/1961 Make: Brantly International, Inc. Model: B-2 | B-2A | B-2B 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: 61-04-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 61-04-01 SUBJECT HEADING: Airworthiness Directives; BRANTLY Models B-2 Helicopters ACTION: SUMMARY: DATES: Effective February 22, 1961. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 61-04-01 BRANTLY: Amdt. 252 Part 507 Federal Register February 10, 1961. Applies to All B-2 Helicopters. Compliance required as indicated. Instances have occurred wherein the centrifugal clutch has failed to release at engine shutdown and subsequent restarting has sheared the bolts which transmit torque from the B2-8-14 clutch disc assembly into the fabric coupling and from the fabric coupling into the lugs of the free-wheeling clutch housing. To preclude recurrence of this condition the following must be accomplished: (a) Within the next 10 hours of flight time after the effective date of this directive, inspect all 6 of the AN 4-10A bolts which secure the fabric coupling to the B2-8-14 clutch disc assembly and to the free-wheeling clutch housing for shear failure. This inspection is to be accomplished by inserting an appropriately sized wrench through the lubrication access hole in the B2-7-17 clutch dust cover and checking each bolt for snugness. Any sheared bolts must be replaced prior to further operation. (b) Within the next 10 hours of flight time after the effective date of this directive a placard shall be installed immediately aft or incorporated with the operating limitations placard located between the fuel mixture control and the carburetor heat control levers to read: "PRIOR TO EACH ENGINE START, TURN ROTOR BACKWARD BY HAND THROUGH 30 DEGREES MINIMUM TO CHECK CLUTCH FREEDOM." The purpose of this placard is to insure that these coupling bolts are not subjected to damage resulting from failure of the clutch to release. (Brantly Service Bulletin No. 6 covers this same subject.) This directive effective February 22, 1961. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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