Anyone who has flown model airplanes for any length of time has had an engine failure, with the resulting distinct “pleasure” of performing a dead-stick landing. It doesn’t matter if the engine is nitro, gas, electric, or a ducted fan—all engines are mechanical and are, therefore, subject to some kind of failure over time. When you are put into this situation, however, the outcome of the approach and landing will greatly depend on your understanding of energy management.
When an airplane loses its engine, it has two basic forms of energy. The first form of energy is determined by the speed of the airplane, which is its kinetic energy. The faster the speed, the greater the kinetic energy. The second form of energy is potential energy, which is determined by the height, or altitude, of the airplane. The higher the airplane, the greater its potential energy.
It’s also important to know that these two forms of energy are interchangeable and that they depend on each other. As an example, if you are in a glide with excess airspeed, you can pull back on the elevator and climb. As the plane climbs it will lose airspeed, which means the kinetic energy of the plane is being transferred into an increase in potential energy. In a similar manner, when in a descent, the potential energy of the plane is being decreased to increase, or maintain, its kinetic energy. This is, unfortunately, not a one-for