AD 93-17-12
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Bell Helicopter Textron, Inc. | 204B | Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. (BHTI) Model 204B, 205A, 205A-1, 205B, 212, and 412 Helicopters |
| aircraft | Bell Helicopter Textron, Inc. | 205A | Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. (BHTI) Model 204B, 205A, 205A-1, 205B, 212, and 412 Helicopters |
| aircraft | Bell Helicopter Textron, Inc. | 205A-1 | Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. (BHTI) Model 204B, 205A, 205A-1, 205B, 212, and 412 Helicopters |
| aircraft | Bell Helicopter Textron, Inc. | 205B | Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. (BHTI) Model 204B, 205A, 205A-1, 205B, 212, and 412 Helicopters |
| aircraft | Bell Helicopter Textron, Inc. | 212 | Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. (BHTI) Model 204B, 205A, 205A-1, 205B, 212, and 412 Helicopters |
| aircraft | Bell Helicopter Textron, Inc. | 412 | Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. (BHTI) Model 204B, 205A, 205A-1, 205B, 212, and 412 Helicopters |
Unsafe Condition
Fatigue failure of the main rotor transmission lower planetary spider (part number 204-040-785-003), which could result in failure of the main transmission and subsequent loss of control of the helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Within 600 hours' time-in-service after the effective date, remove the spider and perform a magnetic particle inspection (MPI) for cracks. Thereafter, inspect at intervals not exceeding 3,100 hours' TIS. Replace any cracked spider before further flight. Alternative methods may be used if approved by the FAA.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 600 hours' time-in-service after the effective date of this AD, unless accomplished previously within the last 2,500 hours' TIS, and thereafter at intervals not to exceed 3,100 hours' TIS.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Bell Helicopter Textron, Inc. Models 204B, 205A, 205A-1, 205B, 212, and 412 helicopters with main rotor transmission lower planetary spider (P/N 204-040-785-003) installed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Main Rotor Transmission Lower Planetary Spider
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_93-17-12.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 93-17-12 Document Type: AD Final Rules Docket Number: 92-ASW-49 Subject Heading: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. (BHTI) Model 204B, 205A, 205A-1, 205B, 212, ...Show more Subject: Main Rotor Transmission Lower Planetary Spider Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 07/29/1994 Make: Bell Helicopter Textron, Inc. Model: 204B | 205A | 205A-1 | 205B | 212 | 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: 93-17-12 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 92-ASW-49 AMENDMENT: 39-8683 AD NUMBER: 93-17-12 SUBJECT HEADING: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. (BHTI) Model 204B, 205A, 205A-1, 205B, 212, and 412 Helicopters ACTION: SUMMARY: DATES: Effective July 29, 1994. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 93-17-12 BELL HELICOPTER TEXTRON, INC. (BHTI): Amendment 39-8683. Docket No. 92-ASW-49. Supersedes AD 92-11-07, Amendment 39-8257. Applicability: Model 204B, 205A, 205A-1, 205B, 212, and 412 helicopters, with main rotor transmission lower planetary spider (spider), part number (P/N) 204-040-785-003, installed, certificated in any category. Compliance: Required as indicated, unless accomplished previously. To prevent fatigue failure of the spider, which could result in failure of the main transmission and subsequent loss of control of the helicopter, accomplish the following: (a) Within the next 600 hours' time-in-service (TIS) after the effective date of this AD, unless previously accomplished within the last 2,500 hours' TIS, and thereafter at intervals not to exceed 3,100 hours' TIS from the last magnetic particle inspection (MPI), remove the spider and perform an MPI for cracks in accordance with the pertinent BHTI maintenance, repair, and overhaul manuals. (b) Replace any cracked spider with an airworthy part prior to further flight. (c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used when approved by the Manager, Rotorcraft Certification Office, FAA, Rotorcraft Directorate. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Rotorcraft Certification Office. NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Manager, Rotorcraft Certification Office. (d) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the helicopter to a location where the requirements of this AD can be accomplished. (e) This amendment becomes effective on July 29, 1994. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_93-17-12.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 93-17-12 Document Type: AD Final Rules Docket Number: 92-ASW-49 Subject Heading: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. (BHTI) Model 204B, 205A, 205A-1, 205B, 212, ...Show more Subject: Main Rotor Transmission Lower Planetary Spider Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 07/29/1994 Make: Bell Helicopter Textron, Inc. Model: 204B | 205A | 205A-1 | 205B | 212 | 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: 93-17-12 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 92-ASW-49 AMENDMENT: 39-8683 AD NUMBER: 93-17-12 SUBJECT HEADING: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. (BHTI) Model 204B, 205A, 205A-1, 205B, 212, and 412 Helicopters ACTION: SUMMARY: DATES: Effective July 29, 1994. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 93-17-12 BELL HELICOPTER TEXTRON, INC. (BHTI): Amendment 39-8683. Docket No. 92-ASW-49. Supersedes AD 92-11-07, Amendment 39-8257. Applicability: Model 204B, 205A, 205A-1, 205B, 212, and 412 helicopters, with main rotor transmission lower planetary spider (spider), part number (P/N) 204-040-785-003, installed, certificated in any category. Compliance: Required as indicated, unless accomplished previously. To prevent fatigue failure of the spider, which could result in failure of the main transmission and subsequent loss of control of the helicopter, accomplish the following: (a) Within the next 600 hours' time-in-service (TIS) after the effective date of this AD, unless previously accomplished within the last 2,500 hours' TIS, and thereafter at intervals not to exceed 3,100 hours' TIS from the last magnetic particle inspection (MPI), remove the spider and perform an MPI for cracks in accordance with the pertinent BHTI maintenance, repair, and overhaul manuals. (b) Replace any cracked spider with an airworthy part prior to further flight. (c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used when approved by the Manager, Rotorcraft Certification Office, FAA, Rotorcraft Directorate. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Rotorcraft Certification Office. NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Manager, Rotorcraft Certification Office. (d) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the helicopter to a location where the requirements of this AD can be accomplished. (e) This amendment becomes effective on July 29, 1994. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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