Here are specs on some .10 powered planes I have built. The Peck Prairie Bird, goofy looking as it is, flew nicely with 423 sq.in. wing area. A Quaker 54 from Penn Valley Hobbies climbed briskly from ROG and had 375 sq.in. area. I built a modernized Miss America from Model Aviation plans which has 500 sq.in. area. It cruised around on part throttle but had difficulty getting rolling on takeoff from grass. With an OS.15 it jumped into the air but had too much power for cruising and was eventually converted to E-power.