# How would one calculate the thrust-to-weight ratio for a minimum turn radius?

I'm looking to calculate the T/W from the minimum turn radius while level, as well as the load factor while banking, and the wing loading W/S

I plan to plot the thrust to weight ratio against wing loading given the inputs mentioned above.

• I don't think that's possible. First of all more often than not to achieve minimum turn radius specified the plane could choose to lose speed. E.g. a glider could give you a minimum turn radius number but it has a thrust to weight ratio of 0. Also even if you manage to get the minimum turn radius with constant altitude and constant speed, you can at most infer lift to drag ratio or lift to weight ratio from it, but not thrust to weight ratio, e.g. for same thrust, at minimum turn radius, thrust equals to drag, so high lift to drag ratio or low weight means small radius. – user3528438 Nov 28 '17 at 15:08

## 1 Answer

You can't. Turn radius is a function of true airspeed & bank angle, and nothing else. A J-3 Cub flying at 40 knots will have a pretty tight turn radius compared to an F-16 with its 9-G turn at 100+ knots, just because the Viper can't approach the Cub's low speed. Or take a KC-135R -- better T/W than a T-38, but not really a low-speed performer nor a high-G machine.

Turn radius in isolation will favor low-speed aircraft over high-speed aircraft, even when the latter have better T:W ratios.