Is it possible these problems may be related to the non-us version of the 12X? I know that the 2.4 is not highly regulated in the gulf nor is highly monitered there, hence may have interference. As suggested, check the same Rx outside the craft with a bunch of servos and compare results with inside the craft... Another way is to install a fut 2.4 in identical location in the jet and see if you get range. Try to change one thing at a time and be scientific about it, not emotional[8D]