Definition
How quickly an airplane's total mechanical energy (the sum of its kinetic energy from speed and potential energy from altitude) is increasing or decreasing at any given moment. It is determined by the balance between thrust from the engine and drag from the airframe: when thrust exceeds drag, total energy rises; when drag exceeds thrust, total energy falls; when they are equal, total energy holds steady.
Plain English
How fast the airplane is gaining or losing its overall 'go and height' combined. Push the throttle forward and you gain energy faster; pull it back or add drag and you lose energy faster.
Context Anchor
Seen in energy management discussions, especially when judging whether the airplane can climb, descend, slow down, speed up, or maintain a stable flight path.
Derivation
Rate means an amount of change measured over time. Energy comes from a Greek word meaning activity or work. Together, the phrase points to how fast the airplane’s ability to keep moving, climb, or descend is changing.
Why Pilots Care
It directly affects whether the aircraft has enough energy to climb, maintain altitude, or descend safely without stalling or overspeeding.
Analogy
It is like watching both your car’s speed and the steepness of the hill at the same time. The important question is not only where you are now, but whether you are quickly gaining or losing the ability to keep going.
Grounding Statement
If thrust is greater than drag, total energy is climbing. If drag is greater than thrust, total energy is bleeding off. The size of that gap sets how fast the change happens.
Intuition Check
Do not read this as only “change in airspeed.” In this FAA context, it means the change in the airplane’s overall energy, including both speed and altitude.
Example Sentence 1
On a stabilized approach, the pilot manages the rate of energy change with the throttle, adding power if the airplane is sinking below the glidepath and reducing power if it is drifting above.
Example Sentence 2
Reducing power makes the rate of energy change negative so the airplane descends at a steady speed.