Originally Posted by
Jetdesign
Edit: yeah I had a mistake in there - wings always have positive (toward canopy) angle relative to the axis of the airplane, so if it's moving forward it's being forced canopy side.
Incidence angle (AOA) is needed for a (symmetric) wing to generate lift, but lift is responsible for flight or climbing. Too much AOA and you stall and lose lift, and fall.
Beat me to it Joe. Lol.
The wing airfoil creates lift. In the case of a flat bottom or semi symmetrical wing, the air speed is faster over the top which creates a low pressure area compared to higher pressure underneath, which creates lift underneath the wing. I suppose if the amount of lift generated is greater than the weight of the model, then it would climb, but generally AOA is what makes the plane climb.
With a fully symmetrical wing, air pressure above and below is the same, so to climb or descend requires the AOA to change. Even with a fully symmetrical wing, AOA is set as positive incidence, which enables the model to fly level without descending. But of course speed also affects the climb rate at a given AOA and or incidence.
Exceed the critical angle of attack and it will stall and fall.
Make sense Joe?