What is indicated airspeed (IAS)?

Indicated airspeed (IAS) is the speed that is shown directly on the airspeed indicator of an aircraft without any corrections for instrument errors or variations due to atmospheric conditions. It reflects the dynamic pressure felt by the aircraft as it moves through the air and serves as a crucial parameter for pilots to ensure safe operations, such as maintaining a proper stall speed and other critical flight maneuvers.

By understanding IAS, pilots can effectively interpret the aircraft's performance in reference to air density and temperature, which is important for safe flight operations. While IAS does not account for factors like altimeter errors or air density changes, it is the fundamental speed reading that pilots rely on for managing flight dynamics.

While the other options refer to relevant concepts in aviation—such as true airspeed, maximum speed, and average speed—they do not accurately describe indicated airspeed as it is understood in flight operations.