If possible -- better go for a good electric setup -at least you can get full motor thrust by just selecting props
We decided this year that anything under a 40 ZDZ--becomes an electric
Our smaller electrics -Hackers 20/20 outrunners will fly a 16 oz model -400 squares like crazy -on 1350 -2100 ma pack.
Just a thought -----
We ran a ski lodge one winter -at Brighton (Utah ) and my poor TR3B was a gutless wonder at that elevation.
I never went back-----