AD 85-07-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Bell Helicopter Textron, Inc. | 412 | Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 412 Helicopters |
Unsafe Condition
Cracks in the main rotor pitch horn assembly P/N 412-010-149-105 and main rotor pins P/N 412-010-180-101 could lead to pitch horn failure.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Visually inspect main rotor pitch horn assembly for cracks within 20 hours time in service after AD effective date, and repeat every 20 hours. Magnetic particle inspect pitch horn if removed. Replace cracked parts and inspect spindle joint before installation. Install newer parts P/N 412-010-149-111 and P/N 412-010-180-103 to avoid further inspections.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 20 hours time in service after the effective date of this AD and thereafter at intervals not to exceed 20 hours time in service from the last inspection
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Bell Helicopter Textron, Inc. Model 412 helicopters, serial numbers 33001 through 33110, equipped with main rotor pitch horn assembly P/N 412-010-149-105 and main rotor pins P/N 412-010-180-101.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Main Rotor Pitch Horn
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_85-07-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 85-07-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 412 Helicopters Subject: Main Rotor Pitch Horn Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 04/10/1985 Make: Bell Helicopter Textron, Inc. Model: 412 Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 85-07-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-5016 AD NUMBER: 85-07-01 SUBJECT HEADING: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 412 Helicopters ACTION: SUMMARY: DATES: Effective April 10, 1985. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 85-07-01 BELL HELICOPTER TEXTRON, INC.: Amendment 39-5016. Applies to Bell Helicopter Textron, Inc., Model 412 helicopters, S/N's 33001 through 33110, equipped with main rotor pitch horn assembly, P/N 412-010-149-105, and main rotor pins, P/N 412-010-180- 101. Compliance is required as indicated, unless already accomplished. To detect possible cracks in the main rotor pitch horn, accomplish the following on Model 412 helicopters equipped with pitch horns, P/N 412-010-149-105: (a) Within the next 20 hours time in service after the effective date of this AD and thereafter at intervals not to exceed 20 hours time in service from the last inspection, visually inspect the main rotor pitch horn assembly for cracks in accordance with Part I of Bell Helicopter Textron, Inc., Alert Service Bulletin (ASB) 412-83-13, Rev. A, dated August 31, 1983. (b) Whenever the main rotor pitch horn assembly is removed for any reason, magnetic particle inspect it for cracks in accordance with Part II of ASB 412-83-13, Rev. A, dated August 31, 1983. (c) If a crack is found during these inspections replace the pitch horn and pins with serviceable parts. (d) Prior to installation of the pitch horn and pins, visually inspect the spindle joint for surface defects and corrosion. Note: Component repair and overhaul manual BHT-412-CR & 0-1, Rev. 4, April 15, 1984, Figure 65-10-5 contains allowable damage limits. NOTE: Further inspections are not required when the following parts are installed: 412-010-149-111 Pitch Horn Assembly -4 required per helicopter. 412-010-180-103 Pin -32 required per helicopter. (Bell Helicopter Textron, Inc., Alert Service Bulletin 412-84-l8, November 19, 1984, pertains to replacement of new horns and pins.) The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth, Texas 76101. These documents may also be examined in the Rules Docket located at the Office of the Regional Counsel, Southwest Region, Federal Aviation Administration, Room 158, Building 3B, 4400 Blue Mound Road, Fort Worth, Texas 76106. Any alternate methods or equivalent procedures must be approved by Mr. James D. Erickson, Manager, Helicopter Certification Branch, ASW-170, Building 3, Room 211, 4400 Blue Mound Road, Fort Worth, Texas 76106. This amendment becomes effective April 10, 1985. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_85-07-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 85-07-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 412 Helicopters Subject: Main Rotor Pitch Horn Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 04/10/1985 Make: Bell Helicopter Textron, Inc. Model: 412 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: 85-07-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-5016 AD NUMBER: 85-07-01 SUBJECT HEADING: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 412 Helicopters ACTION: SUMMARY: DATES: Effective April 10, 1985. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 85-07-01 BELL HELICOPTER TEXTRON, INC.: Amendment 39-5016. Applies to Bell Helicopter Textron, Inc., Model 412 helicopters, S/N's 33001 through 33110, equipped with main rotor pitch horn assembly, P/N 412-010-149-105, and main rotor pins, P/N 412-010-180- 101. Compliance is required as indicated, unless already accomplished. To detect possible cracks in the main rotor pitch horn, accomplish the following on Model 412 helicopters equipped with pitch horns, P/N 412-010-149-105: (a) Within the next 20 hours time in service after the effective date of this AD and thereafter at intervals not to exceed 20 hours time in service from the last inspection, visually inspect the main rotor pitch horn assembly for cracks in accordance with Part I of Bell Helicopter Textron, Inc., Alert Service Bulletin (ASB) 412-83-13, Rev. A, dated August 31, 1983. (b) Whenever the main rotor pitch horn assembly is removed for any reason, magnetic particle inspect it for cracks in accordance with Part II of ASB 412-83-13, Rev. A, dated August 31, 1983. (c) If a crack is found during these inspections replace the pitch horn and pins with serviceable parts. (d) Prior to installation of the pitch horn and pins, visually inspect the spindle joint for surface defects and corrosion. Note: Component repair and overhaul manual BHT-412-CR & 0-1, Rev. 4, April 15, 1984, Figure 65-10-5 contains allowable damage limits. NOTE: Further inspections are not required when the following parts are installed: 412-010-149-111 Pitch Horn Assembly -4 required per helicopter. 412-010-180-103 Pin -32 required per helicopter. (Bell Helicopter Textron, Inc., Alert Service Bulletin 412-84-l8, November 19, 1984, pertains to replacement of new horns and pins.) The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth, Texas 76101. These documents may also be examined in the Rules Docket located at the Office of the Regional Counsel, Southwest Region, Federal Aviation Administration, Room 158, Building 3B, 4400 Blue Mound Road, Fort Worth, Texas 76106. Any alternate methods or equivalent procedures must be approved by Mr. James D. Erickson, Manager, Helicopter Certification Branch, ASW-170, Building 3, Room 211, 4400 Blue Mound Road, Fort Worth, Texas 76106. This amendment becomes effective April 10, 1985. 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.