One of the first things I did with my FC40 was to change the 5.8GHZ TX from CE to FCC by turning the knob on the transmitter. When I did this I got 2 beeps when powering I on. This set the distance from 300 to 500 meters... So I thought.... When plugging in the TX with the RC assistant software, to my surprise it was still set to CE. I had to choose FCC, exit the program, turn off TX, turn on TX, load RC software, and now it was to FCC. I read a post from someone else that had the same issue. This is odd, so FC40, vision and vision + owners, you may want to check this out.