Huge transmission lines give off a huge magnetic circle, so do not fly anywhere near them, meaning 200 yards. Here is what you do, get in your car or truck drive out in the country someplace, stop on the side of the road and take out you Phantom and do the DJI dance, meaning the calibration. Hopefully, you will pick a huge pasture that is flat and has cattle running or feeding in it, no trees, because with trees, you have to gain altitude above them in order to keep your phantom in sight and be sure to keep your antenae pointed at the Phantom while your flying. If your out in the middle of nowhere and can not get your Phantom to calibrate after a few attempts of turning it on and off and all that, then I would say your screwed.