Heck yes my planes are eligible (prayer included). First you have to read the rules, 8.1.3 and 8.1.4 for profile single engine planes. Then it is best to go to several contests, the more the better and get an idea of what the planes entered look like. While your doing these things keep in mind that in Profile scale you get 10 points for scale "appearance" points verses 100 points in Scale class. Now the way I look at 8.1.3 I make sure that from a top view the wings are shaped the way the real planes wings are shaped, and the stabilizer/elevator are shaped the same way. "Area" wise I'm building those two items to compete in the profile carrier event where you need HS, LS, and the ability to take off and land on the deck. Now for the side view of the fuselage I do much the same, tail and rudder look like the real plane, cabin located at the rite place along the length of the fuselage, and the nose is configured to resemble the real plane. The profile silhouette of the fuselage is skinnied (top to bottom) down somewhat while keeping the overall shape similar to the real plane. 8.1.4 is very important and I try very hard to make the colors and decals very similar to the real plane (very important). Or you can build a MO-1 with a 40+inch wing span.