buffeting (the turbulence preceding a stall). Below this speed, the aircraft will be limited to flying at lower g's, resulting in a decrease in turn rate. If the pilot attempts to "pull" more g's, the aircraft will buffet and aerodynamically stall. On the other hand, if the fighter is flown above its corner speed it will be able to pull higher g's, but doing so will cause it to lose airspeed from the excess drag created. Turning at the maximum sustainable-load at speeds above the corner speed will result in an increase in turn radius which, respectively, will cause a decrease in turn rate. "Instantaneous turn-rate" describes turns which are above the maximum sustainable-load. These turns can be as high as 9 g's before the pilot begins to lose consciousness (G-LOC). These turns can have a very small turn radius, but cause a loss in energy, either in the form of speed or altitude. Therefore, these turns are unsustainable, causing the fighter to lose massive amounts of airspeed, sometimes reaching stall speed in as little as a quarter turn. Above the maximum sustained turn-rate, aerodynamic drag exceeds the maximum engine thrust (aircraft has zero "excess power"), meaning aircraft specific energy will be lost even when applying full engine power. Only by turning the aircraft at its best "sustained turn-rate" can the aircraft maintain its specific energy. However, situations in combat may require a change in energy, and energy may also be increased by pulling less than the maximum sustained g-force load. Pursuit curves Successful BFM requires geometry as much as it does skill and stamina. Pilots must know their aircraft's corner speed, as well as optimum angles of bank (AOB) and angles of attack (AOA), without consciously thinking about them. At the same time, pilots must remain conscious of the angle between the opponent's velocity vector and their own, called the track crossing angle (TCA), which is important when aligning or avoiding a firing solution. Most importantly, the pilot must remain aware of the angle off tail (AOT), which is the angle between flight paths. A high AOT causes a high rate of closure, but makes achieving a suitable guns solution nearly impossible. Acquiring a low AOT (getting on an enemy's tail), can decrease or even reverse closure rate, and is usually the primary goal before an overshoot occurs. However, an uncooperative defender may try to take advantage of the