AD 90-21-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | ATR - GIE Avions de Transport R gional | ATR42-300 | Airworthiness Directives; AEROSPATIALE Model ATR42-300 and ATR42-320 Series Airplanes |
| aircraft | ATR - GIE Avions de Transport R gional | ATR42-320 | Airworthiness Directives; AEROSPATIALE Model ATR42-300 and ATR42-320 Series Airplanes |
Unsafe Condition
The propeller brake may overheat and cause damage to the engine.
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Required Actions
Modify the propeller brake electronic control wiring, modify the propeller brake control unit, replace the pushbutton switch with a two-position mechanical switch, install a new brake control unit, install a modified propeller brake, modify the propeller brake indicating logic, or remove the propeller brake as an alternative. Compliance may be adjusted with FAA approval.
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Compliance Time
Within 100 hours time-in-service after May 29, 1989 for paragraphs A-C; within 180 days after October 30, 1990 for paragraphs D-F. Compliance adjustments require FAA approval.
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Affected Aircraft
AEROSPATIALE Model ATR42-300 and ATR42-320 series airplanes, 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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