RE: viper 500 help!
You might try laying something on the grass like a piece of carpet upside down. We used to do this at pylon races years back when flying at sodfarms. If powered properly you will have no problem getting off of the ground. Let it go at full throttle and hold full up elevator until you break the ground. Make sure you CG is right on. If you are nose heavy you will have trouble. Landing should pose no problems. Just try not to come in too fast.