The Rockwell Collins 590A-3J Air Data Control is used in the FCS-105 Flight Control System, FCS-112B Flight Control System, FD-108X Integrated Flight System, and the FD-108Y Integrated Flight System. The 590A-3J provides an analog error signal to the flight control system that is proportional to the altitude hold error. The 590A-3J also supplies true airspeed, indicated airspeed, and altitude programming voltages for flight control system use. The altitude error gain may be programmed with indicated airspeed, altitude, true airspeed altitude, or set at a fixed value.

The convection cooled 590A-3J is housed in a 3/8 ATR short, low black case that is textured with epoxy coating.  The 590A-3J is 3.74 inches wide, 3.49 inches high, 15.1 inches deep with the handle extended and weighs 4.2 pounds maximum. The 590A-3J operates in an altitude range of -1,000 feet to +60,000 feet and a temperature range of 55°C to +71°C.