I built a Falcon 56 in 1970, initally powered with an OS .19 and three channels of an Orbit proportional. It flew great with three channel, and I later converted it to four. It was a pretty easy to fly design, I landed it on it's first flight (my first RC airplane). On the second flight, I made the takeoff and the instructor landed it. The third flight was solo, and that was the extent of my flight training. Later on I upped the power to a ST G21-35. Great design from the past.