AD 90-01-11
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Bell Helicopter Textron, Inc. | 204B | Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 204B Helicopters |
Unsafe Condition
Failure of the tail rotor duplex bearing set, P/N 204-040-424-001, could result in loss of tail rotor control and subsequent loss of the helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove the tail rotor gearbox duplex bearing set, P/N 204-040-424-001, within 100 hours' time in service after the effective date and replace with a serviceable part before further flight. The helicopter may be flown to a base where AD requirements can be accomplished with FAA approval.
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Compliance Time
within 100 hours' time in service after the effective date of this AD
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Affected Aircraft
Bell Helicopter Textron, Inc. Model 204B helicopters with tail rotor gearbox duplex bearing sets P/N 204-040-424-001, serial numbers 1 thru 182, MB183 thru MB382, MB442, MB486, MB513, MB518, MB519, MB524, MB530, MB531, MB544, MB545, MB548, MB549, MB551, MB553, MB554, MB561, MB659, MB743, MB744, MB760 thru MB769, and MB927 thru MB936.
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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