Another newbie here, and I like to keep mine probably 10-15 feet off the ground. Ironically, as in your experience, my Diablo's worst damage has been sustained from crashes while flying about 3 feet off the ground, including two bent booms. The one crash I had from about 12 feet up resulted in damage that took about 10 minutes to fix (broken blades and a bent spindle, IIRC).