Tescoapp, you're talking about stopping a prop, not stalling it in the aerodynamic sense. In simple terms a propeller is just few wings stuck onto a hub. In the same way as you stall a wing by taking it beyond the critical angle, you stall a prop by increasing its pitch relative to the airflow. You can do this by either increasing the pitch at a given airspeed or reducing the airspeed (to zero in my example above) at a given pitch.
As an aside, the twist that you see in propeller blades (coarse pitch at the root, fine at the tips) is there because the inner portions are travelling more slowly than the outboard portions, thus requiring a higher blade angle to achieve the angle of attack necessary to generate significant lift (i.e. thrust).
Last edited by DB6; 11th December 2004 at 08:03.