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Final rule.

The Federal Aviation Administration is amending the airworthiness standards applicable to certain transport category airplanes certified for flight in icing conditions and the icing airworthiness standards applicable to certain aircraft engines. The regulations will improve safety by addressing supercooled large drop icing conditions for transport category airplanes most affected by these icing conditions; mixed phase and ice crystal conditions for all transport category airplanes; and supercooled large drop, mixed phase, and ice crystal icing conditions for all turbojet, turbofan, and turboprop engines.

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