Aircraft specific energy

Aircraft-specific energy is a form of specific energy applied to aircraft and missile trajectory analysis. It represents the combined kinetic and potential energy of the vehicle at any given time. It is the total energy of the vehicle (relative to the Earth's surface) per unit weight of the vehicle. Being independent of the mass of the vehicle, it provides a powerful tool for the design of optimal trajectories. Aircraft-specific energy is very similar to specific orbital energy except that it is expressed as a positive quantity. A zero value of aircraft-specific energy represents an aircraft at rest on the Earth's surface, and the value increases as speed and altitude increases. As with other forms of specific energy, aircraft-specific energy is an intensive property and is represented in units of length since it is independent of the mass of the vehicle.