Definition
An electronic device in modern aircraft that gathers raw air-pressure and temperature inputs from the pitot tube, static ports, and outside air temperature probe, then calculates and outputs flight parameters such as airspeed, altitude, vertical speed, Mach number, and true air temperature to the cockpit displays and other aircraft systems.
Plain English
A small computer that takes pressure and temperature readings from sensors on the outside of the aircraft, does the math, and feeds your speed, altitude, and climb-rate information to the instruments.
Context Anchor
Seen in aircraft with digital flight displays, especially when studying how altitude, airspeed, and climb or descent information reaches the instrument panel.
Derivation
"Air data" refers to information about the air the aircraft is moving through -- its pressure, temperature, and how fast the aircraft is passing through it. The ADC is simply the computer that processes this air data into useful flight information.
Why Pilots Care
Supplies accurate real-time flight data needed for safe instrument flying and autopilot operation.
Intuition Check
An ADC is not an autopilot and does not fly the airplane. It calculates air-related information so the pilot and aircraft systems can use it.
Example Sentence 1
After takeoff, the pilot noticed the airspeed and altitude on the primary flight display had frozen, suggesting a possible ADC failure.
Example Sentence 2
Before takeoff the pilot confirms the air data computer is receiving valid sensor inputs.