Reminds me of my woodshop teacher sharing his UC Ringmaster on the football field during one class after we built HLG in the class.  What a treat to see this 60 powered plane fly in a circle doing wing overs and reverse flying inverted.  Our instrutor was a very talented circle flyer.  He shared with us his all aluminum P-51D he won for winning a contest!!  Set me on my modeling course for the rest of my life.  Went through those dime scale kits rubber powered, UC, FF, then after college into the IPMS (Internation Plastic Modelers Society).  Much later into RC till kids arrived then everything went on hold in the modeling arena.  Much later a return to Free Flight Rubber rubber powered models.  Sorry for getting long winded.  Your stories of your dad brought back wonderful memories. Thanks!!!

Dad, with his drone diesel on a zipper, and I'm guessing a O&R 19 on the other one. Then dad in The Navy, CVA 41 Midway, 1954.
He told me the drone was easy to start and run, and they flew it on a golf course in Lexington Ky(try that now!)...after launching, she climbed out, then started circling, and kinda dipping, came back around and buzzed them!...I'm guessing tail heavy, but he said it was neat for a bunch of boys.....