Airspeed Indicator, 900 km/h, Luftwaffe Fahrtmesser Fl.22234 Lily Bomber or an internal engine-driven compressor)

or an internal engine-driven compressor) and the system of pneumatically-powered flight instruments

to be sure

used by bombardiers and technicians to check the proper operation of the Norden Bombsight

where the master switch is a flat toggle instead of a push/pull switch as designed in this B-6

This valve was used to regulate the vacuum pressure between its source (either an externally-mounted venturi tube

Airspeed Indicator, 900 km/h, Luftwaffe Fahrtmesser Fl.22234 Lily Bomber or an internal engine-driven compressor)Here 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