Are you at least 20 miles from anyone or anything that you could potentially hurt? You need to realize that these things are not toys. If you lose orientation (which is very likely), you may think your plane is flying back toward you, when it is in fact flying away. By the time you realize this, it's out of sight, and out of range. Your plane will most likely fly at least 40 mph, and probably faster. At 40 mph and 15 minutes, it would travel a minimum of 10 miles. With a larger tank, or faster airspeed, you could approach 20 miles before it comes down. That is how innocent people/property get hurt. So, saying you're going to fly this "on your own sand" is a farce. Good luck, though.