The Ultra-Zap, as we call it, is a concept model of a full size electric powered ultralight. The idea took shape as a napkin sketch when Scott and I had the opportunity to sit down with the designer of the Kolb line of full size sport aircraft, Homer Kolb. After watching us fly a few of our electric powered RC aircraft at an event last fall, Homer asked us if we thought it would be possible to power an ultralight with an all up weight of 254 pounds. Scott crunched some numbers and determined it could be done with off the shelf components.   

Our twin engine design allows for two large out runners with separate speed controls and banks of batteries. Power input on the full sized plane would be about 11,000 watts per motor. A pusher configuration was chosen for the unobstructed view. The main landing gear, engine pods and tail boom all tie to the spar center section. 

That talk with Homer intrigued us into building a RC model to test some of our ideas. The Ultra-Zap was designed first at full size then scaled down to what we thought would be a decent indoor model. I have built many scale and sport models and played around with some of my own designs but this was a whole new experience for me to design an aircraft around an average size pilot. Scott had located a couple of cute little out runners that weighed just 10 grams each. The finished model has 192 sq. in. of wing area and weighs just over 7 oz. A two cell 480 mah battery provides the power for both motors. The models motors are about 13 watts per motor. Castle Creations ThunderBird 9 amp speed controls provide throttle control. Variable throttle for yaw control is mixed in the radio and operates via the rudder stick.