ORIGINAL: mydartswinger

This may be a newbie post, but has anyone had any experience with helis such as the blade cx/cp or heli-max axe ez/cp in elevations close to 1 mile up? I've never flown in a high elevation environment, and I'm thinknig about having my heli sent to me. I'm wondering if such a high elevation would keep any of the above birds on the ground. I have the Axe CP, but there is at least one other person here that has a blade cx. He's been having trouble getting it more than a couple of inches off of the ground. Then again, is cx needs a bit of work to. Thanks for any input.