Radius of turn R = TAS squared, divided by (g x tan AoB)
Circumference of circle = 2 x pi x R
If TAS = V, time to cover 360 deg is thus 2 x pi x R / V
i.e. 2 x pi x (V squared / (g x tan AoB)) / V
or for n degress, n/360 of this time:
i.e. (n x 2 x pi x V) / (360 x g x tan AoB)