Below is a brief story Dick Kline emailed us in 2009 about the the KF Airfoil and Condor Airplane:-----------------------------------------------------Here's the brief story on The Condor.When I developed my first stepped airfoil, it had the step on thebottom. I was pleased with the way it flew, but like so many of us, Iwanted to experiment some more once I nailed down the step on thebottom. When I placed it on the top I found out that it produced higherlift than the one on the bottom. It would climb higher and travel alonger distance. Later tests at Notre Dame confirmed that the step onthe top was able to generate higher lift over drag. I then playedaround with placing the elevators on the upper surface just in front ofthe rudder. After many different experiments and many different flightsI had perfected The Condor, which would be the plane I would use tochallenge the Wright Brothers distance record. In spite of very strongwinds coming in off Cape Hatteras, I was successfully able tooutdistance the distance record for the first manned flight of 122feet. I did this in 1985 down in Kill Devil Hills, NC right on the spotwhere the Wright Brothers first flew. My distance was 401 feet, fourinches. On the fourth flight that day of the Wright Brothers historicflight they traveled quite a bit further, so I was lucky that theirfirst flight was just 122 feet.Here is the data from the wind tunnel at Notre Dame. It would have beena lot higher if we had a rounded leading edge and a little camber. Butwe were interested in seeing exactly what the step produced by itself.Later, everyone would follow this configuration out the window and getpoor results. This was our big mistake. But we also knew at that timethat the step worked in different configurations and we couldn't patentthem all. All we wanted was to patent a step in the hopes that it wouldproduce stall resistance to other airfoils. All the experts trashedthis idea as too high in drag, yet the KFm4, with a step on the top anda step on the bottom, increases the speed of the wing. If the drag wasso high, how could this be?All in all, it has been a wonderful adventure and I feel very gratefuland lucky for it. I have come in contact with many truly wonderfulpeople in the RC community. From my perspective, the world could takesome lessons from the RC people on how to work together, how to openlyshare information and knowledge freely and produce an environment ofcreativity and experimentation. This way everyone benefits and thelearning curve climbs way up for everyone.The gentleman who conducted these tests at Notre Dame was ProfessorJohn D. Nicolaides, the first head of NASA.