Airspeed Indicator, 900 km/h, Luftwaffe Fahrtmesser Fl.22234 Lily Bomber When the de-icing system is

When the de-icing system is engaged by flipping a toggle switch

When viewing the ground through the scope while in flight

Its a terrific historical document

thus following the airspeed index on the inner scale

The bracket has one spirit level to ensure that the gunsight body is level perpendicular to the line of flight

Airspeed Indicator, 900 km/h, Luftwaffe Fahrtmesser Fl.22234 Lily Bomber When the de-icing system isHere is a WW2 era German Airspeed Indicator FI. 22234, with a maximum airspeed of ~900 km h. As the airspeed increases, rotating the pointer clockwise from the 6 o'clock position, it rotates 360deg past 0 once 800 km h is exceeded, thus following the airspeed index on the inner scale, up to ~900 km h. According to AircraftCockpits. com, this was used in aircraft such as Do335, Fi103, FW190A7 9, Ta152, Go229, He162, He219, Ju388, Bf109G, Fi103, and