Known icing

KNOWN ICING
FAA certified to fly into icing conditions.
KORFU
(FuG 351) German ground radar often used to produce fixes on the bombers H2S equipment.

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AFM in the limitations section precudes flight into known icing.
A PIREP is the only way that a pilot can know of 'known icing'.
When the tops and bottoms of clouds exceed 4000' there is ice in there.

Only aircraft allowed to fly in known icing conditions can legally do so, it may not be smartest thing to do, however. Rain can turn to snow real quick and hide important navigation details on the ground.

You are guaranteed that the equipment has been demonstrated to provide adequate ice protection only if the aircraft is certified for flight into known icing conditions.

See also: Altitude, Speed, Radar, Track, Wing