Definition
A flight path in which the airplane maintains the same horizontal distance from a fixed point on the ground throughout a turn or series of turns, producing a perfectly circular ground track regardless of wind.
Plain English
Flying so that your distance from a chosen spot on the ground stays the same the whole way around, drawing a true circle over the ground.
Context Anchor
Used when practicing a steep spiral around a selected ground reference point, such as a field chosen for a simulated emergency landing.
Derivation
From Latin 'radius', meaning the spoke of a wheel or the line from the center of a circle to its edge. 'Constant' means unchanging. Together: an unchanging spoke length — the airplane's distance from the center point never changes as it goes around.
Why Pilots Care
Maintains a predictable ground track, prevents drifting into obstacles, and allows controlled airspeed and descent rate.
Intuition Check
Constant radius does not mean holding the same bank angle all the way around. It means keeping the same distance from the point on the ground, even if the bank has to change to correct for wind.
Example Sentence 1
During the steep spiral, the pilot adjusted bank angle throughout each turn to maintain a constant radius around the chosen ground reference point.
Example Sentence 2
Proper wind correction kept the spiral path at a constant radius instead of letting it stretch into an oval.