Definition
An autopilot or flight director vertical control mode in which the system commands a pitch attitude that holds a selected indicated airspeed (IAS) during a climb or descent, rather than holding a fixed vertical speed or altitude. In helicopters equipped with stability augmentation or autopilot systems, this mode is often required or restricted by the Rotorcraft Flight Manual for certain phases of instrument flight.
Plain English
A setting on the autopilot that tells the aircraft to keep flying at a chosen airspeed by raising or lowering the nose, instead of trying to hold a steady climb rate or altitude.
Context Anchor
Seen in helicopter flight manual limitations and in procedures for using an autopilot or flight director during instrument flight.
Derivation
Indicated comes from a Latin root meaning “to point out” or “show.” In aviation, indicated airspeed is the speed shown by the airspeed indicator, so the word reminds the pilot that this mode follows the displayed airspeed, not ground speed or true airspeed.
Why Pilots Care
Reduces pilot workload and improves speed stability during instrument approaches and departures.
Intuition Check
Indicated does not mean the helicopter’s actual speed over the ground; it means the speed shown on the airspeed indicator. Mode does not mean the whole aircraft is automatic; it means this one selected function is active.
Example Sentence 1
The flight manual required the pilot to engage indicated airspeed mode for the climb to the missed approach altitude.
Example Sentence 2
In indicated airspeed mode the helicopter automatically adjusted pitch to hold the target speed during the climb.