High voltage transmission lines pose peculiar hazards to low flying aircrafts. International civil aviation organization FAA specifies that such structures should be marked and lighted. Due to non-availability of conventional power supply on transmission lines stand alone solar powered red Medium intensity or combination of medium and low intensity aviation warning lights are being used to mark the towers for night time. Cable warning sphere or span markers in red, orange & white are being used to mark the earth-wire for day time marking. Due to the high voltage running through the conductor & its presence in remote locations, it needs specially trained service engineers to install, test and maintain the obstruction lights.