Hi rfw1953
What happened goes like that: My friend, and the owner of a MVVS 2.15 petrol mounted it on a brand new giant plane he made (he produces fiberglass models). This giant's wings span almost 10' and its a really impressive model. This was supposed to be the maiden flight of the new model and the engine. The radio we used was Futaba PCM (bad choice for gasser). The installation of the engine, ignition and received was ok (over 8 distance). I tested for range with engine both idle and full RPM and it looked ok. I wanted to program the failsafe but my friend who is a stubborn mule dismissed me as being paranoidic. I decided I would still do that once the ground break-in finishes. I went to get something from my car when I noticed him taxiing the plane to the runway. I asked if he was going to take off and he said he only wants to taxii the plane to figure out the handling etc. I guess he then had a short circuit in his brain because instead of taxiing he decided to take off. The plane gained speed and he lifted off. Once about 20' off ground the radio locked and he went full throttle into ground. A post mortum revealed that neither the plug nor the ignition assembly had a series resistor, which can account to the radio lockout. The wing survived and is in service now on a second plane he made (he didn't break the mold after he made the first one...). The engine was converted to glow and is working flawlessly and very powerful (over 4HP with 20x8 prop).