AD 86-12-01 L
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Bell Helicopter Textron, Inc. | 214ST | Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 214ST Helicopters |
Unsafe Condition
Loss of main rotor collective control due to a defective locking plate (Part Number 214-010-232-101) or improper torque of the lower collective hub nut (Part Number 214-010-407-001).
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Required Actions
Visually inspect the locking plate per Part I of ASB 214ST-86-36. Check torque of the lower collective hub nut per Part IV of the same service bulletin. Subsequent inspections at each 'A' and 'B' checks per Parts II, III, and IV of the service bulletin.
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Compliance Time
prior to further flight after receipt of this AD
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Affected Aircraft
Bell Helicopter Textron, Inc. Model 214ST helicopters, all serial numbers, certified in all categories.
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Federal Register Abstract
Locking Plate
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_86-12-01_L.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 86-12-01 L Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 214ST Helicopters Subject: Locking Plate Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Bell Helicopter Textron, Inc. Model: 214ST Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 86-12-01 L CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 86-12-01 L SUBJECT HEADING: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 214ST Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 86-12-01 BELL HELICOPTER TEXTRON, INC.: Letter issued June 6, 1986. Applies to all Bell Model 214ST helicopters, certificated in all categories. Compliance is required prior to further flight after receipt of this AD, unless previously accomplished. To prevent loss of main rotor collective control, visually inspect locking plate, Part Number (P/N) 214-010-232-101, in accordance with Part I of Bell Helicopter, Textron, Inc., Alert Service Bulletin (ASB) 214ST-86-36, dated May 23, 1986. If the locking plate is defective, check the torque of the lower collective hub nut, Part Number 214-010-407-001, in accordance with Part IV of ASB 214ST-86-36. At the next "A" check, inspect the locking plate in accordance with Part II of ASB 214ST-86-36. At each subsequent "A" check, inspect the locking plate in accordance with Part III of ASB 214ST-86-36. At the next "B" check and each subsequent "B" check, check the torque of the lower collective hub nut, P/N 214-010-407-1, in accordance with Part IV of ASB 214ST-86-36. An alternate method of compliance or adjustment of the compliance time, which provides an equivalent level of safety, may be approved by the Manager, Helicopter Certification Branch, Aircraft Certification Division, FAA, Southwest Region. This airworthiness directive becomes effective upon receipt. FOOTER:
Document Text
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AD Final Rules - DRS_86-12-01_L.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 86-12-01 L Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 214ST Helicopters Subject: Locking Plate Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Bell Helicopter Textron, Inc. Model: 214ST 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: 86-12-01 L CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 86-12-01 L SUBJECT HEADING: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 214ST Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 86-12-01 BELL HELICOPTER TEXTRON, INC.: Letter issued June 6, 1986. Applies to all Bell Model 214ST helicopters, certificated in all categories. Compliance is required prior to further flight after receipt of this AD, unless previously accomplished. To prevent loss of main rotor collective control, visually inspect locking plate, Part Number (P/N) 214-010-232-101, in accordance with Part I of Bell Helicopter, Textron, Inc., Alert Service Bulletin (ASB) 214ST-86-36, dated May 23, 1986. If the locking plate is defective, check the torque of the lower collective hub nut, Part Number 214-010-407-001, in accordance with Part IV of ASB 214ST-86-36. At the next "A" check, inspect the locking plate in accordance with Part II of ASB 214ST-86-36. At each subsequent "A" check, inspect the locking plate in accordance with Part III of ASB 214ST-86-36. At the next "B" check and each subsequent "B" check, check the torque of the lower collective hub nut, P/N 214-010-407-1, in accordance with Part IV of ASB 214ST-86-36. An alternate method of compliance or adjustment of the compliance time, which provides an equivalent level of safety, may be approved by the Manager, Helicopter Certification Branch, Aircraft Certification Division, FAA, Southwest Region. This airworthiness directive becomes effective upon receipt. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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