What is the primary function of a CRT in an EFIS?

The primary function of a Cathode Ray Tube (CRT) in an Electronic Flight Instrument System (EFIS) is to display alphanumeric data and represent various aircraft instruments visually. The CRT provides pilots with critical flight information, such as airspeed, altitude, heading, and navigation data, in a format that is easy to interpret.

This display plays a vital role in enhancing situational awareness and reducing the pilot's workload, as all necessary information is presented on a single screen rather than across multiple analog instruments. This integration of data helps pilots make informed decisions quickly, improving safety and efficiency in flight operations.

The display technology behind the CRT has been largely replaced by more advanced technologies like LCDs (Liquid Crystal Displays) and OLEDs (Organic Light Emitting Diodes) in modern EFIS systems, but its fundamental role in providing intuitive visual representations remains a key aspect of flight instrumentation.