AD 94-17-15
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Enstrom Helicopter Corporation, The | 280 | Airworthiness Directives; The Enstrom Helicopter Corporation Model F-28A, F-28C, F-28C2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | 280C | Airworthiness Directives; The Enstrom Helicopter Corporation Model F-28A, F-28C, F-28C2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | 280F | Airworthiness Directives; The Enstrom Helicopter Corporation Model F-28A, F-28C, F-28C2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | 280FX | Airworthiness Directives; The Enstrom Helicopter Corporation Model F-28A, F-28C, F-28C2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | F-28A | Airworthiness Directives; The Enstrom Helicopter Corporation Model F-28A, F-28C, F-28C2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | F-28C | Airworthiness Directives; The Enstrom Helicopter Corporation Model F-28A, F-28C, F-28C2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | F-28C-2 | Airworthiness Directives; The Enstrom Helicopter Corporation Model F-28A, F-28C, F-28C2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | F-28F | Airworthiness Directives; The Enstrom Helicopter Corporation Model F-28A, F-28C, F-28C2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
Unsafe Condition
Delamination and extrusion of the main rotor feathering elastomeric Lamiflex bearing (part numbers 28-14320-12 or 28-14320-15) causes loss of flight control system feedback dampening, leading to sudden increases in vibration, flight control feedback, and degradation in flying qualities, potentially resulting in complete delamination and subsequent loss of control.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Within 5 hours' time-in-service, inspect the Lamiflex bearing for delamination. Repeat inspections every 100 hours' TIS or annually. Replace bearings if delamination is found, if undated, or after 5 years from manufacture. Use Enstrom Service Directive Bulletin 0081, Rev A for procedures.
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Compliance Time
Required as indicated, unless accomplished previously. Compliance is tied to specific time-in-service intervals (5 hours, 100 hours) or annual inspections.
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Affected Aircraft
Enstrom Helicopter Corporation Models F-28A, F-28C, F-28C2, F-28F, 280, 280C, 280F, and 280FX series helicopters equipped with Lamiflex bearings part numbers 28-14320-12 or 28-14320-15.
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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