Thank you.
Oh,I forgot to give some informations.Mine uses 140RX with 4000 cc. stock tank that can fly about 8-9 mins per flight with average 70 % of throttle stick.For control throws value to maiden flight,I used values from skymaster viper-L manual
these are Ele=20 mm.,Rud=25mm.,Ail=15mm.,Flap take off= 15 degree and Flap landing = 45 degree.
I think it 's a little fast for me,so l reduced to 80 % of the original throws.My viper can take off by using about 150-200 m. of runway length.
In my opinion,140 engine size is match with this model with no options like smoke system or moving pilot.If you want vertical performance and carry more options,you should try 160 size.