Another newbie question

On Fri, 16 Jan 2009 10:22:27 -0500, wrote in :

Dihedral tends to cause the airplane to bank when yawed and to return to wings-level flight when the yaw input is removed.

Dihedral will probably tend to reduce the effectiveness of the ailerons. Lots of airplanes have both dihedral and ailerons. Building the flat wing will help separate the yaw-roll controls (rudder and aileron) from each other.

I'd recommend making a commitment to learning how ailerons work. Build the wing flat and go for it. :o)

Marty

Martin, I just remembered what caused my hair line to recede.... smacking my forehead when the obvious dawns! Thank you, I'll take your advice. Going a step further, if I understand yaw and lift in a dihedral wing, then the removable leading edge "droops" that some flat winged aileron trainers come equipped with serve a function similar to dihedral.

On Sat, 17 Jan 2009 08:10:50 -0500, "Randy" wrote in :

Let us know how it turns out. Nothing like a little reality check to help trim the wild unruly growth of theories. :o)

I don't think so, although I haven't examined the droops myself.

The kind of droop device I am imagining is the leading edge cuff:

This is symmetrical on both sides of the plane and doesn't introduce any dihedral effects (i.e., the cuff isn't itself tapered from root to tip). What it does is increase lift and drag. This means that the stall speed of the aircraft will be lower as well as the top speed--the entire flight envelope is shifted toward the lower end of the spectrum which, arguably, is good for beginners. When the cuffs are taken off, the plane has to be landed faster and may be flown faster which, arguably, is good for intermediate pilots.

Or the droops may be the equivalent of leading edge slots:

Some airliners have got moveable leading edge slats. You can watch them come out as the plane is configured for landing.

You can see several photos of the leading edge slats of the F-100 Super Sabre on this page:

These slats would come out at low speeds to allow slower landings but would retract at higher speeds to reduce drag.

Marty

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As Marty has pointed out, leading edge slats are more of a low speed enhancing feature.

Dihedral is a stabilizing feature, helping keep the aircraft flying with its wings level with the horizon and coincidentally keeping the aircraft's flight path somewhat in a straight line.

Ed Cregger