I have noticed that a lot of the larger sail planes are Carbon Fiber and 2.4 does not transmit through Carbon Fiber very well. So FM with an antenna works better in some cases. I lost my 50cc gas plane due to 2.4 failure. The company tried to blame it on optical kill switches. Yes I had a solid power supply, all of my stuff was new. I did not use a optical kill and it failed still. I have used my 2.4 radio and can duplicate the process with my gas engine. I have used it with nitro and electric and no problems. I have tested it with a junk plane with my 50cc gas engine. It seemed to have no problems. I flew and got several good flights and it browned out on the ground, I was lucky. I just will not use my radio with gasoline engines again. Just goes to show brand name radios can be lemons too.