I had a patriot with a Estes D in the tail end I used a 9 volt Nike battery and a micro servo to fire the engine. I usually used the rocket engine on take off. It was a sight to see. I would start to rotate after 50 feet and the climb out was awesome! They make special engines for glider use I think they are D11P's The reason for this is no exhaust gases go forward. I sealed the forward engine mount bulk head and used some D-12-0 boosters I had. the rocket motor weighs a couple of ozs so make sure your CG doesn't get to far back. After the engine fires you notice a shift in CG.