Wheel and Flap Position Indicator, AN5780-3, 8DJ26AAA Air Forces of USA The venturi is a tube

The venturi is a tube shaped like a double "V" and has a small opening

see page from its pilot manual dated 1944

since all that is required of him is the proper response to its indicators without the necessity of making any mental computations

and used on into the 1950's

Wheel and Flap Position Indicator, AN5780-3, 8DJ26AAA Air Forces of USA The venturi is a tubeThis is a late WWII era Wheel and Flap Position Indicator, Type AN5780 3, as used in aircraft of the US Army Air Force with either tricycle landing gear (i. e., nose wheel) or tail wheel configurations. According to the Maintenance Interchangeability Chart dated Feb 1945, late models of medium bomber B 26 Marauder, attack bomber A 20 Havoc, and night fighter P 61 Black Widow used this indicator. This particular indicator has a serial number prefix of