Old thread I thought I would answer...
AxisLock mode is like Rate mode but will "come back" to the original angle if disturbed. It was mainly designed for heli tails.
You would probably want to adjust some of the AxisLock settings. For instance there is a setting that says if it gets more than 30 degrees wrong that it will give up and lock on to the new angle and not try to get back to the old angle.
And of course it does not control the throttle and if you don't have enough throw in the surfaces and don't have enough throttle to hover it may be physically impossible for the FC to hold the angle.
Be careful what you do with this. For instance if just put on rudder, you will have to coordinate turns (use the rudder) just to get it to fly normally. No bank and yank. If put on elevator, it will try to hold whatever ridiculous angle you have asked for. If you set the max angle really high you may have asked it to point straight up but it is floundering around with not enough power to ever get pointed straight up and you not knowing what angle it is trying to hold. If you have it on elevator, a long takeoff is such a case. If you hold up elevator during the take off run, then suddenly when it finally gets enough speed, all the integrated angle from you holding up elevator so long (the elevator surface probably went to full up by now) shows up and it does really crazy things. Always have a safe mode on your FMS that you can take off with and switch to if it not acting right.