HI GJAUBIN! One of the most difficult things to see is when you are flying too slowly to stay airborn. When you are flying downwind it is more dangerous to fly slowly because you have less wind flowing front-to-back past your wing. You have to experiment up high with stalling your wing on purpose so that you can gauge what your minimum speed needs to be. It takes a trained eye to see when youv'e reached that minimum speed. The controls will get less responsive as a warning. Your model should be balanced laterally to help make sure that stalls aren't as much wingtip stalls as they are" nose down "stalls. Not reacting soon enough with the throttle has sent a lot of planes to the landfill.