AD 90-17-02
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Enstrom Helicopter Corporation, The | 280 | Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28, F-28A, F-28C, F-28C-2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | 280C | Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28, F-28A, F-28C, F-28C-2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | 280F | Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28, F-28A, F-28C, F-28C-2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | 280FX | Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28, F-28A, F-28C, F-28C-2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | F-28 | Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28, F-28A, F-28C, F-28C-2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | F-28A | Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28, F-28A, F-28C, F-28C-2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | F-28C | Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28, F-28A, F-28C, F-28C-2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | F-28C-2 | Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28, F-28A, F-28C, F-28C-2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | F-28F | Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28, F-28A, F-28C, F-28C-2, F-28F, 280, 280C, 280F, and 280FX Series Helicopters |
Unsafe Condition
Loss of tail rotor thrust and directional control due to failure of five-plate flex-pack couplings (Dana Corp. P/N A005-1991) could result in substantial damage or loss of the helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Within 5 hours' time in service after the effective date, inspect tail rotor drive shaft couplings and log part numbers, hours, and date. Remove any five-plate couplings before further flight, inspect and replace flanges if deformed, and install seven-plate flex-pack coupling (Enstrom Kit No. 28-01041-1). Thereafter, inspect seven-plate couplings every 100 hours' time in service for distortion and airworthiness limits, replacing them if exceeding limits or reaching 1,200 hours' time in service.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 5 hours' time in service after the effective date of this AD, and before further flight for removal of five-plate couplings. Subsequent inspections at 100-hour intervals.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Enstrom Helicopter Corporation Models F-28, F-28A, F-28C, F-28C-2, F-28F, 280, 280C, 280F, and 280FX series helicopters certificated in any category.
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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