Range (aeronautics)

The maximal total range is the maximum distance an aircraft can fly between takeoff and landing, as limited by fuel capacity in powered aircraft, or cross-country speed and environmental conditions in unpowered aircraft. The range can be seen as the cross-country ground speed multiplied by the maximum time in the air. The fuel time limit for powered aircraft is fixed by the fuel load and rate of consumption. When all fuel is consumed, the engines stop and the aircraft will lose its propulsion. The maximal total range is the maximum distance an aircraft can fly between takeoff and landing, as limited by fuel capacity in powered aircraft, or cross-country speed and environmental conditions in unpowered aircraft. The range can be seen as the cross-country ground speed multiplied by the maximum time in the air. The fuel time limit for powered aircraft is fixed by the fuel load and rate of consumption. When all fuel is consumed, the engines stop and the aircraft will lose its propulsion. Ferry range means the maximum range the aircraft can fly. This usually means maximum fuel load, optionally with extra fuel tanks and minimum equipment. It refers to transport of aircraft without any passengers or cargo. Combat range is the maximum range the aircraft can fly when carrying ordnance. Combat radius is a related measure based on the maximum distance a warplane can travel from its base of operations, accomplish some objective, and return to its original airfield with minimal reserves. For most unpowered aircraft, the maximum flight time is variable, limited by available daylight hours, aircraft design (performance), weather conditions, aircraft potential energy, and pilot endurance. Therefore, the range equation can only be calculated exactly for powered aircraft. It will be derived for both propeller and jet aircraft. If the total weight W {displaystyle W} of the aircraft at a particular time t {displaystyle t} is: W {displaystyle W} = W 0 + W f {displaystyle W_{0}+W_{f}} , where W 0 {displaystyle W_{0}} is the zero-fuel weight and W f {displaystyle W_{f}} the weight of the fuel (both in kg), the fuel consumption rate per unit time flow F {displaystyle F} (in kg/s) is equal to − d W f d t = − d W d t {displaystyle -{frac {dW_{f}}{dt}}=-{frac {dW}{dt}}} . The rate of change of aircraft weight with distance R {displaystyle R} (in meters) is d W d R = d W d t d R d t = − F V {displaystyle {frac {dW}{dR}}={frac {frac {dW}{dt}}{frac {dR}{dt}}}=-{frac {F}{V}}} , where V {displaystyle V} is the speed (in m/s), so that