Turnups, I've not seen many fly worth a darn. They are too big IMHO for 1/2A power.
Another good flyer for 1/4A is George Gassaway's Fish n Chips glider. It is small enough that it might even work with mmx (1/8A) motors, although I have not tried that at this point. I don't know if he has the plans for that on on his website or not (he posted it to our club's private message board).
The Fish N' Chips does fly better than it was named (the origins go way back to an MIT design from the 70's, created IIRC by Chris Flanigan).
I have done a few sizes. The size I have flown the most is what I had named "Big" Fish N' Chips, only because it was a little bigger than the MIT original. Have used that for 1/2A and A B/G many times thru the years. Here is the plan as a 2-page PDF.
I will also attach a GIF version in 2 pages.
The one Greg mentioned was sized for 1/4A power. Our team used it to win 1/4A B/G at NARAM last year. I will attach a one page plan for it, as a GIF, and the PDF version link is here:
Back to 1/2A and A, I sometimes used light 3/32" balsa for the wing for 1/2A, and light 1/8" balsa for A power. Because the wing might shred on A power if it is 3/32".
My best performer has been one that I made around 10 years ago for NARAM. For the wings, I used meat tray foam (about 1/8" thick or a bit more), with Japanese Tissue vac-bagged onto the foam to make the foam stiffer. Low viscosity laminating epoxy was squeegeed onto the tissue and then squeegeed off, leaving the tissue "damp" with epoxy, minimizing weight. Then the tissue was laid in place on both sides of the wings and the wings were put into a vacuum bag and the pump turned on. The vacuum process sucked the peel-away plastic into the tissue to press them into the foam to make them bond, it is not practical to use epoxy to bond the tissue to the foam any other way (it would add too much weight to try to use epoxy in the same way a person would use clear dope to apply tissue on a balsa wing). The pump was left on left for the epoxy to cure fully overnight. The result was a set of light wings and stiff wings with a very smooth surface. Even though I built it for 1/2A, those wings were strong enough for A power. It has placed in several NARAMs holding 1/2A and A power, and won A B/G in 2004. Attached are pics of the wings in the vac bag and the completed glider. I do not mention this expecting people to go as far as vacuum bagging wings, but that's what I've done and that sure solved the 3/32" for 1/2A and 1/8" for A problem.
- George Gassaway