I read over and over don't fly near powerlines and especially don't calibrate your compass near powerlines. How close is too close? This theory is way too vague for me. In the typical city there are powerlines everywhere. I am talking about the "standard" ones not the mega huge high voltage ones. Please give me some rules of thumb! After loosing my first Phantom within 2 weeks of buying it I plan to be extra cautious in the future.