Peacemaker

The Peacemaker (such a good plane IMHO) has a relatively small cambered wing chord followed by a large flat sheet area. Why does this work so well - as opposed to a larger fully cambered wing?
By the way I'm new to this forum. UK based. Fly diesels PAW 15 & 19 and Fox 35. Just built Box Car Chief - waiting for weather to settle before maiden flight. Last of the summer wine vintage (me not the plane!). Just love control line.....
Adrian

Agree your comments re the way the Profile Peacemaker flies, and I have wondered this myself. A starting point might be to make a Peacemaker keeping the wing thicknesses the same, but with full airfoil section extended back to the T.E., and see if it flies any different? Er.. over to you.

Of course, the FlightStreak does the same thing.

What do you mean by "cambered"? The part that doesn't include the "fixed flaps"? Or is the foil behind the high point a flat surface to the trailing edge? Phil Cartier's been using airfoils with flat rears for a while, and I've been copying him. I've heard all sorts of Combat airfoil gurus says that that'll never work, but it does. It's great when you're covering the wing - you can lay it down on a flat surface while ironing on the covering.

The Peacemaker and Flightstreak have a straight chord
wing (no taper) with the flat-plate extensions on the back.
Look like big flaps, but they don't flap.
With the extensions, the wings taper.

The airfoil is symmetrical, no camber, and consistent
across the span of the wing. Except for the little extensions.

Pretty simple to build, and apparently effective.
I guess the original questions is: Why is such a simple design so good?

Flitestreak might fly good because of:
thick wing, low weight,efficient wing tip, short nose/tail for low inertia. Stationary flaps can think of several ideas, however not an engineer so I'll pass.

Ah.. so that is what is meant.

It approximates the old "polliwog" (tadpole) airfoils, I suppose, and Phil did some experiments with those. He says a polliwog airfoil improved turning on Combat planes. I imagine they're a pain to cut and cover in foam, though, and would be weak in the trailing edge.

Consider also that pretty much all flapped Stunt planes have the same airfoil, except that the polliwog's tail moves. Al Rabe did some tests years and years ago, hoping to prove that non-polliwog flaps (where the flaps were a continuation of the wing's airfoil instead of just being sheet balsa) would work better, but he got the opposite results - the sheet flaps work better.