Radar Indicator Lens, AN/APG-33 and-40 Radar for E-1 Fire Control System FJ-2 But this is immediately noticeable

But this is immediately noticeable

The fluid is low by about a teaspoon

This is a Cold War-era Airspeed Indicator

which could be attached to either a vertical or horizontal surface of the aircraft

Radar Indicator Lens, AN/APG-33 and-40 Radar for E-1 Fire Control System FJ-2 But this is immediately noticeableWhile called a "Flight Indicator" on its label, this is essentially the radar scope lens for the AN APG 33 and 40 Radar Systems of the E 1 Fire Control System developed by Hughes Aircraft for the US Air Force. These systems were put into use on the Northrup F 89 Scorpion and Lockheed F 94 Starfire Fighter Interceptors in the 1950's. See images of the scope on the F 94 and the F 89 (instrument panel from the F 89 flight manual). Made by Hughes