I live at 6500ft and was curious how autogyros fly at high elevation.

Physics is that the higher the air the less dense, the less dense air makes it harder for rotor blades to provide lift.

What the practical effects are on a model auto gyro I'm not sure.

Ive flown a DC gyro in bogota, colombia, at 8300 ft, no problem, except I used a .40 OS instead of the .25 recommended. It flyes great, but it takes a bit to get it spinning. Here's a video of it. http://www.youtube.com/watch?v=hgPj6...&feature=g-upl