to their own advantage. Energy management In combat, a pilot is faced with a variety of limiting factors. Some limitations are constant, such as gravity, structural integrity, and thrust-to-weight ratio. Other limitations vary with speed and altitude, such as turn radius, turn rate, and the specific energy of the aircraft. The fighter pilot uses BFM to turn these limitations into tactical advantages. A faster, heavier aircraft may not be able to evade a more maneuverable aircraft in a turning battle, but can often choose to break off the fight and escape by diving or using its thrust to provide a speed advantage. A lighter, more maneuverable aircraft can not usually choose to escape, but must use its smaller turning radius at higher speeds to evade the attacker's guns, and to try to circle around behind the attacker. BFM are a constant series of trade-offs between these limitations to conserve the specific energy state of the aircraft. Even if there is no great difference between the energy states of combating aircraft, there will be as soon as the attacker accelerates to catch up with the defender. However, potential energy can easily be traded for kinetic energy, so an aircraft with an altitude advantage can easily turn the potential energy into speed. Instead of applying thrust, a pilot may use gravity to provide a sudden increase in speed, by diving, at a cost in the potential energy that was stored in the form of altitude. Similarly, by climbing the pilot can use gravity to provide a decrease in speed, conserving the aircraft's kinetic energy by changing it into altitude. This can help an attacker to prevent an overshoot, while keeping the energy available in case one does occur. Turn performance Both turn rate (degrees per second), and turn radius (diameter of the turn), increase with speed, until the "corner speed" is reached. Corner speed is defined as the minimum speed at which the maximum sustainable g-force load can be generated (the load at which power equals drag), and varies with the fighter's structural design, wing loading characteristics, weight (including added weight from missiles, drop-tanks, etc...), and thrust capabilities. It often falls in the area of . The maximum sustainable-load the aircraft can generate also varies, but is typically between 3 and 5 g's. At the corner speed, the fighter can attain its maximum turn-rate, flying the craft just at the edge of