The US40 ARF comes with two sets of ailerons. One set is full span for conventional ailerons. You could use that with the flaperon feature on the DX7 to get ailerons and flaps. Or you can install the quad flap option and utilize more complex programming to get features such as crow.

Since you've built this with the 4 flap option, do you have 4 servos in the wing? You can fly it just fine by leaving the servos to the inboard flaps unplugged and stationary. Just fly with the outboard ailerons operating as normal.

FWIW, you can fly the US40 with the quad-flap arrangement with a 7 channel radio and receiver but you might be lacking some mixes to get it to do everything it's capable of.

I fly the US40 with my JR X9303 2.4GHtz system. It's programmed per H9 [link=http://www.horizonhobby.com/ProdInfo/Files/JR_9303_Ultra_Stick_Programming.pdf]documentation[/link] on their website.