If I could add my $.02, I have built and flown two of the Proctor Nieuport 11 aircraft over the years. I used 2-stroke .60 engines on both, with 14/4 props and had no issues with take off or flying authority. As with any WWI aircraft, make sure it is balanced a bit nose heavy and keep the speed up on landing. Right rudder during takeoff and cross controlling during flight was pretty much necessary for scale competition. I take off my WWI aircraft with a slow build up of throttle, coupled with right rudder and a bit of aileron for balance. The Proctor designs are excellent flying machines. I watched Whitney perform very well with his plane during the Connecticut Biplane Event this past September and it brought back many memories. This post has me back on my 50% framed up 1 1/2 Strutter...Laser .70 for power. Happy holiday season to all. Regards, George