MAx Rate Turns

[Nozzles]

Gentlemen,

To clear up some definitions for those who asked:

An aeroplane's Best Instantaneous Rate of Turn occurs at the minimum speed that will generate airframe-limiting g. Because it is the minimum speed at which this occurs, you will be in the light buffet. In fighter parlance this speed is known as Corner Velocity, and gives you your highest rate of turn in terms of degrees per second. It does not give you the aircraft's minimum turn radius. Most aeroplanes do not have the power-to-weight ratio to maintain this in a level turn, and so, as has been previously discussed, the Instantaneous turn tends to be a spiral-hence its name-you can't keep it up for ever.

The Best Sustained Rate of Turn is the maximum turn rate that can be achieved whilst maintaining level flight. This occurs at a slower speed than Corner Velocity, and is known as a 'Power (or Thrust) Limited Turn'. This is because the amount of back-pressure you apply creates just enough drag to match your thrust, and thus the aeroplane can maintain both the airspeed and the turn rate. It is short of the light buffet, and the turn rate can be temporarily improved by pulling to the light buffet (the top of the CL curve). However, for most aeroplanes, this will result in a bleeding of speed and an eventual reduction in turn rate.

A Minimum Radius turn occurs at an even slower speed than either of the above. As an aeroplane slows down for a given g loading, its turn radius will decrease. There is a point on the graph at which, if you slow down further, the reduction in radius the slower speed should give you is offset by the reduced turning capability provided by the dwindling g. This point is Min Radius Speed. It usually occurs in full flap configurations as this configuration gives the highest lift harvest for the lowest speed input.

I would like to echo the previous recommendations that such stuntery is NOT attempted without proper training.