well i gues my F86 and easytigers flew great , i live in southern california , i had no problem , 30% power master heli fuel in the middle of the desert at aprox. 2500 feet alttitude , it did take alittle time to take off aprox. 100 Feet , i let it build some speed nice and level and turn right , and she was on step after that , iwas able to get the little F86 so high that i need it to bring it down cause i was losing site of it , and this one is stock ,for those that dont believe , Me and my bud that also has one of this little buggers ,will be at the tucson rally this weekend ,so come and see for your self .Ed