Here’s some flying Greek from a flying geek:
| α | alpha | Angle of attack | The vertical angle between the oncoming air and the zero-lift line of the wing, as shown (partly and imperfectly) by the airspeed indicator. |
|---|---|---|---|
| β | beta | Sideslip | The horizontal angle between the oncoming air and the aerodynamic centreline of the aircraft, as indicated (partly) by the inclinometer (the ball in the turn coordinator). |
| γ | gamma | Flight path angle | Angle of the flight relative to the earth. When you fly an ILS approach, you’re following a constant gamma angle, even if your alpha and THETA vary. |
| Γ | GAMMA | Geometric dihedral angle. | Vertical angle of the wings as they extend away from the fuselage. Normally the wing tips are higher than the roots, to improve roll damping, especially on low-wing planes. |
| δ | delta | Control surface deflection angle | I.e. CLδe is the contribution of elevator deflection to the coefficient of lift. In a plane with direct control linkage (rods or cables), you could theoretically determine control surface deflections directly from the position of the yoke and/or rudder pedals. |
| ε | epsilon | Downwash angle | The most important example is the angle of the downwash from the wings hitting the horizontal stabilizer. |
| θ | THETA | Pitch angle | The aircraft’s rotation in the pitch axis, as read off the attitude indicator. |
| Λ | LAMBDA | Sweep angle | Horizontal angle of the wings relative to a line perpendicular to the aircraft centreline (does that even make sense)? LAMBDA is usually close to zero on slower planes — sweep doesn’t do much until you get transsonic. |
| ϖ | pi | ~3.14 | You were expecting, maybe, chopped liver? |
| ρ | rho | Air density | As in 0.5ρv2 in the dynamic pressure equation you had to memorize in ground school. |
| σ | sigma | Sidewash angle | The horizontal angle of air deflected to hit a surface of the plane (think of downwash, and it might make sense — I cannot think of a good example, though). |
| Φ | PHI | Airplane bank angle | Rotation in the roll axis, as read off the attitude indicator. |
| Ψ | PSI | Airplane heading angle | Rotation in the yaw axis, as read off the compass. |
(I hope that the Greek characters show up in your browser.)
This is only a selection — if you want more (much more), grab a used copy of Jan Roskam’s Airplane Flight Dynamics and Automatic Flight Controls, part one, which I used as a reference for this list.
Land and Hold Short 