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.
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.