I have noticed that the newer double engine planes require "power pack" engines that can be purchased at the store. Still not a good flier as I would like to be. I have a few engines from earlier swappable planes (FT Flyer, Nutball, Delta) that can still be used, but not sure if there is a double engine plane that I can use them on. Many ideas come to mind but still not sure if these engines can be used. Any suggestions?