Change the batteries and fly it. Yea, right! I tried that - luckily the servos went nuts before I started moving. I still haven't found the problem but have been told it could be in either the transmitter or the receiver or maybe even a servo or two.. Seriously, do a compelte check of your radio system, inlcuding range check before you fire up your engine. Then do it again after your fire it up.
BTW, one thing you will find with 2.4GHz is that unlike 72MHz nearly evey manufacturer has their own comm protocols and therefore one manufacturers receivers won't work with another's transmitter. That's one disadvantage to Frysky, Flysky and the cheapy Chinese ones. I was looking at a Flysky 9 channel system yesterday but found that it came with an 8 channel receiver and couldn't find a 9 channel receiver for it.