Bugzilla is correct.

The thin air at 6200 ft (Colorado Springs) is a real challenge to those of us that fly marginally nitro powered heli's. You really need to
overpower then to get them to fly here. The electrics do not have as much of an issue because the nitro engines loose about 30% of
their power here. The air is still less dense and the rotors still do not work as well here. I've never seen anyone increase the blade
pitch as you get higher in altitude.

Fixed pitch heli's are not very good above 6000ft. There just isn't enough adjustability in them to tuneable higher than that. Most of the people that know how to tune them are already flying collective pitch machines already.

I've made various adjustments on the realflight simultors to try and fly at 6000ft. I've lowered the engine power to around 70% and then had to lower the blade pitch from the regular 11 degrees to 9.5 to 9.0 degrees. The high angle of attack (11 degrees) on the blades pulls to much engine power. Once I lower the pitch it flies similar to how mine flies at the same settings.

James in CO