Definition
An altitude at which two airplanes — one in level flight and one in a climb or descent — possess the same total mechanical energy, where the kinetic energy of airspeed and the potential energy of altitude balance out to the same sum. At this height, the slower, higher airplane and the faster, lower airplane hold equivalent energy states, even though their speed and altitude differ.
Plain English
A point where one airplane that is high and slow has the same total energy as another that is low and fast. Different mix of altitude and speed, but the totals match.
Context Anchor
Seen in energy management discussions, especially when learning how pitch and power affect altitude, airspeed, climbs, descents, and glide control.
Derivation
Energy comes from a Greek word meaning activity or work. Height means vertical distance. In this term, the airplane’s speed energy is converted into an equivalent amount of height, so altitude and speed can be compared on the same scale.
Why Pilots Care
Allows a pilot to recognize when two different flight states carry the same total energy, supporting precise decisions about power and pitch to maintain desired approach or glide performance.
Analogy
Think of having the same amount of money split between cash and a bank account. One person may have more cash and less in the bank, while another has less cash and more in the bank, but the total amount can still be the same.
Grounding Statement
Two aircraft can carry the same total energy in different forms — one as height, the other as speed — and that total is what matters when you need to convert between them.
Intuition Check
Equal energy height does not mean the airplanes are at the same actual altitude. It means their combined altitude-and-speed energy is the same when expressed as a height.
Example Sentence 1
A high, slow airplane and a low, fast airplane can be at the same equal energy height if their combined altitude and airspeed energies add up the same.
Example Sentence 2
By recognizing equal energy height, the pilot knows a descent can be continued at constant power while trading altitude for speed without gaining or losing total energy.