Definition
A ground-reference maneuvering concept in which the airplane's flight path traces a circle of unchanging radius over the ground while turning, requiring the pilot to continuously vary bank angle to compensate for the effect of wind on groundspeed throughout the turn.
Plain English
Flying a turn so that the path you trace on the ground stays the same distance from a chosen point all the way around. Because wind pushes the airplane faster or slower over the ground at different points in the turn, the pilot has to keep adjusting how steeply the airplane is banked to hold that even circle.
Context Anchor
Used in ground reference maneuvers, especially turns around a point, where the pilot practices controlling the airplane’s path over the ground while wind is affecting it.
Derivation
"Constant" means unchanging; "radius" is the distance from the centre of a circle to its edge. Together they describe a circle that stays the same size. The phrase is used here in its literal geometric sense, applied to the airplane's track over the ground rather than through the air.
Why Pilots Care
Develops precise control of ground track, prevents unintentional drift toward obstacles or off course, and builds the wind awareness required for safe airport operations.
Analogy
It is like walking in a circle around a flagpole while keeping the rope between you and the pole tight. If something pushes you sideways, you have to adjust your path to keep the same circle.
Grounding Statement
Picture flying a circle around a silo on a windy day: when the wind is behind you, you are moving fast over the ground and need to bank steeply to keep from being blown wide; when you are flying into the wind, you are moving slowly over the ground and need to shallow the bank so you do not cut inside the circle.
Intuition Check
Constant radius does not mean holding the same bank angle. It means holding the same distance from the center point; in wind, the bank angle usually has to change.
Example Sentence 1
During turns around a point, the instructor reminded the student that maintaining a constant radius during turning flight requires the steepest bank when directly downwind of the reference point.
Example Sentence 2
Before the checkride the student flew several circles maintaining constant radius during turning flight to show accurate wind correction.