Definition
A pilot input error in which the airplane's total energy state — the combination of altitude (potential energy) and airspeed (kinetic energy) — is mismanaged for the phase of flight, leaving the airplane with too much or too little energy to safely complete the intended maneuver.
Plain English
The pilot ends up with the wrong mix of height and speed for what they are trying to do — for example, too high and too fast on final approach, or too low and too slow when trying to climb. The airplane has the wrong amount of usable energy at the wrong time.
Context Anchor
Used in energy management discussions, especially during approaches, descents, climbs, and maneuvering when the pilot is judging whether the airplane is high, low, fast, or slow.
Derivation
Energy here is borrowed from physics: the airplane stores energy as height (potential) and as speed (kinetic). An energy error means the pilot has let those stored amounts drift away from what the situation requires.
Why Pilots Care
Uncorrected energy errors produce unstable approaches, excessive sink rates, runway overruns, or stalls.
Grounding Statement
Think of altitude as money in the bank and airspeed as cash in your pocket. An energy error means you have the wrong total, or the wrong split between the two, for what you are about to spend.
Intuition Check
Energy Error does not mean an electrical problem, and it does not simply mean the pilot made a mistake. Here, energy means the airplane’s speed and height, and error means they do not match what the airplane needs right now.
Example Sentence 1
Arriving at the final approach fix high and fast, the pilot recognized the energy error and went around rather than try to salvage the approach.
Example Sentence 2
A low energy error on short final required immediate addition of power to avoid landing short of the runway.