The Simplex was designed by Paul Plecan and published in the February 1941 issue of Air Trails magazine. Paul reported that his original model was lost on its eleventh flight when it flew Out-of-Sight in 33 minutes on a 15-sec. engine run. For those wishing to avoid the chase, a Park Flyer version of the Old Time Free Flight Clasic is available for electric RC with rudder, elevator and speed control. Flying weight with a 2/830 LiPo is 7 1/2 oz. Recommended power is the HC-2208 brushless (M-112) and 9 amp speed control (C-M-112) . 2 micro servos (HS-55) will be required to complete this model for RC park flying.