BFM: 1 vs 2 circle fights
So, one circle and two circle is related to radius of turn vs rate of turn. A plane which can turn with a smaller radius can get inside the turn circle of a plane with a larger radius, thus its better in a one circle fight. A plane with a better turn rate prefers two circle because it can get around the circle faster than the other guy.
Good turn radius often relates to good slow speed handling and a better ability to turn well at low speed. Planes with lots of lift and lower wing loading should be better at this.
Turn rate is helped by low drag, high thrust, and high max G.
For a couple examples: Viper has high thrust, low drag, high G, and has an AOA limiter. Not great at one circle, king of two circle. The Hornet has high lift, great AOA controllability, but more drag and less thrust than the Viper. Better at one circle. Mirage has high thrust and low unloaded drag, and high G, but also very high drag in a turn. It has great instantaneous turn, but it’s turn rate falls off as it loses speed quickly at high G. However The delta wing gives it great slow speed maneuverability too and it can unload and regain energy well. So it’s great at one circle but can also hang in two circle or vertical fights if energy is managed well.
So, one circle and two circle is related to radius of turn vs rate of turn. A plane which can turn with a smaller radius can get inside the turn circle of a plane with a larger radius, thus its better in a one circle fight. A plane with a better turn rate prefers two circle because it can get around the circle faster than the other guy.
Good turn radius often relates to good slow speed handling and a better ability to turn well at low speed. Planes with lots of lift and lower wing loading should be better at this.
Turn rate is helped by low drag, high thrust, and high max G.
For a couple examples: Viper has high thrust, low drag, high G, and has an AOA limiter. Not great at one circle, king of two circle. The Hornet has high lift, great AOA controllability, but more drag and less thrust than the Viper. Better at one circle. Mirage has high thrust and low unloaded drag, and high G, but also very high drag in a turn. It has great instantaneous turn, but it’s turn rate falls off as it loses speed quickly at high G. However The delta wing gives it great slow speed maneuverability too and it can unload and regain energy well. So it’s great at one circle but can also hang in two circle or vertical fights if energy is managed well.