The planes are easily build, cheap to make and could be made into an RC plane with a little experimentation. It has to be able to glide carrying the weight of your rc system. This is the same method employed by Orville and Wilbur. When their glider could out glide the birds carrying an extra 120Lbs they knew it could fly with a motor. Please let me know if any of this will work for you. What you are doing is great but not everyone will be helpful. Good luck

HI Pastor
here is a link to a STEM project I worked on to introduce aviation to highschoolers. I am a big fan of the Wright Brothers so the program starts with the method of the WB to learn from the birds, build gliders, experiment with wings and learn what makes a plane fly well. Your problem is to make it so very light that it can fly slowly inside. This is why you should start with gliders. Check out the plans PDF it is for a glider that can be made from two foam meat trays (250 for $30) a chop stick and hot glue. I like to make the wings so they are held on with rubber bands so the kids can build and try different wings. The links to glider physics will show you how to test for best glide ratio. Best glide ratio = slower flight.