The angle between the wing's chord line and the oncoming air. A bigger α usually makes more lift; until the wing stalls.
Lift Coefficient (CL)
A number that describes how efficiently a surface makes lift at the current α. The wing and the tail each have their own CL. In a stable airplane like the Super Cub the tail usually produces downward lift (negative CL) in normal cruise flight.
Mean Aerodynamic Chord (MAC)
The "average" chord length of the wing, used as a reference ruler. CG and NP are reported as a percentage along the MAC (0% = leading edge, 100% = trailing edge).
Center of Gravity (CG)
The balance point of the aircraft. The white needle on the slider is the current CG position.
Moving weight around inside the plane shifts it.
Note: These CG limits are shown for maximum gross weight (1750 lb).
At lighter weights the forward limit moves forward (more forward CG is allowed).
Neutral Point (NP)
The CG location where the aircraft becomes neutrally stable. If the CG passes the red tick mark, the plane will stop self-correcting its pitch.
Static Margin
The distance from the CG to the Neutral Point, measured in % MAC. Think of it as the pitch-stability safety buffer; larger margin means more stable and easier to fly.
Pitching Moment (Cm)
The twisting force (torque) that rotates the nose up (+) or down (−) around the CG.
Cm is based upon the real physical pitching moment M (lb·ft), it turns into a unitless (UL) coefficient Cm; a value that is “normalized” removing the effects of speed, size, and air density making it small and easy to use.
Stability Slope (ΔCm/Δα)
The slope of the Pitch Stability. It measures how Cm changes as α changes. Negative = stable (returns to trim), flat = neutral, positive = unstable (pitches further away).
Trim
The stabilizer setting pilots adjust to make Cm = 0 at a target α. Trim handles the steady-state work so the pilot doesn't have to hold elevator pressure.
Pitch Attitude
The aircraft's orientation relative to the horizon (nose up, nose down, banked). The vertical indicator next to the simulation shows pitch attitude in real time.