A. The radio altimeter (RA) system supplies vertical position data for use by the pilots for runway approach, landing, and takeoff. The RA system provides accurate measurement of absolute altitude (height
above terrain) from 2500 ft. to touchdown. Altitude data is routed to user systems on 429 digital data buses.
B. Three complete systems are installed. Each system consists of areceiver/transmitter (R/T), and one transmit and one receive
antenna. Altitude data is displayed on the electronic attitude
director indicators (EADIs)and on tape radio altitude indicator if equipped.