What instrument will be affected if the air data computer fails in an aircraft with an electronic flight display?

In an aircraft equipped with an electronic flight display, the air data computer (ADC) plays a vital role by processing information related to air pressure, airspeed, altitude, and other critical flight data. When the ADC fails, it disrupts the flow of this essential data to various instruments, particularly affecting the airspeed indicator.

The airspeed indicator relies directly on the data provided by the ADC, which calculates the dynamic pressure from the aircraft’s speed through the air. Without this information, the airspeed indicator cannot function properly, leading to incorrect readings or total failure. This makes the airspeed indicator especially susceptible to malfunctions when the ADC is compromised.

Other instruments such as the altitude indicator, heading indicator, and vertical speed indicator may still have some level of redundancy or backup systems to maintain functionality in the absence of accurate air data from the ADC. Therefore, among these choices, the airspeed indicator is the most directly impacted by an ADC failure.