An icing detector is disclosed for detecting presence of ice in static air. An exemplary detector includes an ice collecting surface; a light emitter for emitting a light beam crossing an ice collecting surface, having a prismatic light manipulating window for internally-reflecting the light beam when no ice is present on the ice collecting surfaces, and externally-refracting the light when clear ice is present on the ice collecting surface, wherein the ice collecting surface is oriented to cause standing water to be directed away from the prismatic light manipulating window by gravity; a light sensor in a path of the reflected light; and an annunciator coupled to the light sensor for annunciating the presence of ice when light is sensed by the light sensor.