Definition
The paths an airplane can follow as it moves between different combinations of altitude (potential energy) and airspeed (kinetic energy), based on how the pilot manages pitch and power. Each trajectory represents a possible way to gain, lose, or trade energy during flight.
Plain English
The different paths your airplane can take as it climbs, descends, speeds up, or slows down, depending on how you use the controls and throttle. Think of it as the routes available to you for changing your height and speed.
Context Anchor
Seen in energy management discussions when visualizing how an airplane can move between one combination of speed and altitude and another.
Derivation
From 'energy' (the airplane's stored height and speed) and 'trajectory' (Latin trajectoria, meaning a path or course followed). Together: the path the airplane follows as its energy changes.
Why Pilots Care
Understanding energy trajectories helps pilots plan power and pitch changes to avoid low-energy situations that lead to stalls or runway overruns.
Grounding Statement
At any moment, the airplane has a certain amount of altitude and airspeed; an energy trajectory is the path it takes as those two values change.
Intuition Check
Do not read trajectory as only the airplane’s curved path over the ground. Here it means the airplane’s path between combinations of speed and altitude as its energy changes.
Example Sentence 1
By reducing power and lowering the nose slightly, the pilot followed an energy trajectory that traded altitude for a small gain in airspeed.
Example Sentence 2
Adding full power during a go-around shifted the airplane onto a climbing energy trajectory that increased both speed and altitude.