How Bank Angle and Turn Radius for Rate turns is computed
Turn Radius (R) is a function of the Bank Angle and is proportional to the square of the True Air Speed (TAS). That is, when the True Air Speed doubles, the Turn Radius is four times greater, and when the True Air Speed is tripled, the turn radius becomes 9 times greater, etc.
The Bank Angle required for such a turn can be calculated by solving for Bank Angle i.e. re-arranging the equation given above.
A standard rate turn or Rate 1 turn is 3°/sec (180°/min) and allows for a reversal of course within 1 minute. A Rate 2 turn is 6°/sec, 360°/min) and allows a full 360 orbit in 1 minute. A Rate 1-half turn is that that of a Rate 1 turn at 1.5°/sec (90°/min) and is a turn through 90 degrees in one minute.
How Turn Radius is computed
Rate of Turn (ω) is defined as degrees of heading change per second. The Bank Angle (θ) used in the turn is directly proportional to True Air Speed (TAS).