Plain English Meaning
The aircraft is flying steadily, not speeding up, slowing down, climbing harder, descending harder, or turning. Speed and direction are holding constant.
Full Definition
A flight condition in which the aircraft is not undergoing any change in speed or direction — meaning airspeed is constant and the flight path is steady, with all forces acting on the aircraft in equilibrium.
Context Anchor
Seen in aircraft performance discussions, especially when comparing how much power is needed at different airspeeds in the region of reversed command.
Derivation
‘Accelerate’ comes from the Latin accelerare, meaning ‘to hasten’ or ‘to speed up.’ In physics, includes any change in speed or direction, not just speeding up. So ‘unaccelerated’ means no change is occurring in either — the aircraft is in .