Stall strips DA20

[JulienD]

Hi everybody,

I have a question regarding the functiun of the stallstrips of the DA20.

The wikipedia difinition of stallstrips is:

A stall strip is a small sharp-edged device that, when attached to the leading edge of a wing, encourages the stall to start there in preference to any other location on the wing. If attached close to the wing root, it makes the stall gentle and progressive; if attached near the wing tip, it encourages the aircraft to drop a wing when stalling.

On the DA20 they are mounted close to the wingtips, so beside the fact that they are used to create a buffet felt via the ailerons on the control stick, why would you want at the stall to have a wingdrop ? Which could be quite dangerous if a good remedial action (=use of rudder) is not taken ???

Thanks you in advance for your help.

[FlyingStone]

The things you see at the leading edge near the wing tip on the DA20 aren't stall strip, but rather turbolators. Their job is to increase aileron effectiveness at low speeds - and DA20 is indeed fully controllable only with ailerons down to stall speed. The DA20 actually doesn't require any actual stall strips (near the wing root as you mentioned), because the stall is actually quite benign, until/unless you help with rudder :E

The turbolators change laminar flow to turbulent flow, thus delaying separation point and making ailerons still effective at low speeds. Since detailed aerodynamics is not really my field of expertise/interest, I'll leave more detailed explanation to someone else :)