AD 94-18-09
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Bell Helicopter Textron, Inc. | 205A | Airworthiness Directives; Bell Helicopter Textron, Inc. Model 205A, 205A-1, 205B, 212, and 412 Series Helicopters |
| aircraft | Bell Helicopter Textron, Inc. | 205A-1 | Airworthiness Directives; Bell Helicopter Textron, Inc. Model 205A, 205A-1, 205B, 212, and 412 Series Helicopters |
| aircraft | Bell Helicopter Textron, Inc. | 205B | Airworthiness Directives; Bell Helicopter Textron, Inc. Model 205A, 205A-1, 205B, 212, and 412 Series Helicopters |
| aircraft | Bell Helicopter Textron, Inc. | 212 | Airworthiness Directives; Bell Helicopter Textron, Inc. Model 205A, 205A-1, 205B, 212, and 412 Series Helicopters |
| aircraft | Bell Helicopter Textron, Inc. | 412 | Airworthiness Directives; Bell Helicopter Textron, Inc. Model 205A, 205A-1, 205B, 212, and 412 Series Helicopters |
Unsafe Condition
Fatigue failure of the main transmission lower planetary spider (spider) 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
Remove and replace the spider with an airworthy unit per specified Alert Service Bulletins. Spiders with 2,400+ hours TIS on the effective date must be replaced within the next 100 hours TIS. Spiders with less than 2,400 hours TIS must be replaced prior to or upon reaching 2,500 hours TIS.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 100 hours TIS (for spiders with 2,400+ hours TIS on effective date) or prior to reaching 2,500 hours TIS (for others).
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Bell Helicopter Textron, Inc. Models 205A, 205A-1, 205B, 212, and 412 series helicopters with main transmission lower planetary spider part number 412-040-785-101 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
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