In flight dynamics, theta represents the pitch attitude of an aircraft. It measures the angle between the longitudinal axis of the fuselage and the true horizontal. Flight control systems and autopilot algorithms use this variable to calculate climb rates, descent profiles, and overall aerodynamic stability.
Heard on the job
The flight data recorder showed a theta of positive 15 degrees right after rotation.
Do not mix it up with
- Angle of attack: Theta is the angle of the aircraft relative to the horizon, while angle of attack is relative to the oncoming air.
Related terms
Angle of attack
The acute angle between the chord line of an airfoil and the oncoming relative wind.
Artificial horizon
A primary flight instrument that shows the aircraft's pitch and roll relative to the earth's horizon.
Gamma
The flight path angle represents the angle between an aircraft's velocity vector and the horizontal plane.