AD 88-09-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Bell Helicopter Textron, Inc. | 214ST | Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 214ST Helicopters |
Unsafe Condition
Cracks in the tail rotor intermediate gearbox mounting lugs could result in loss of tail rotor control and subsequent loss of directional control of the helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Within 25 hours' time in service after the effective date, inspect the three gearbox mounting lugs for cracks. If cracks are found, use fluorescent or dye penetrant inspection and replace the gearbox if cracks exist. Verify washer stack-up, torque bolts to 100-140 in-lbs, and resecure with safety wire. Within 250 hours' time in service, remove and inspect the gearbox for cracks, barrier tape, wear, and damage; remove barrier tape, replace parts as needed, clean surfaces, apply primer, and reinstall with proper torque and safety wire. After completing the 250-hour inspection, the 25-hour inspections are no longer required.
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Compliance Time
Within the next 25 hours' time in service after the effective date of this AD, and thereafter at intervals not to exceed 25 hours' time in service; and within the next 250 hours' time in service after the effective date for the second inspection.
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Affected Aircraft
Bell Helicopter Textron, Inc. Model 214ST helicopters certificated in any category.
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Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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