It will create a lightning discharge path regardless if you fly it over the cloud layer. 1 kg/km • 50 km • 9.8 m•s^-2 • 50 km = 24.5 MJ 10 MJ = kinetic energy

It will create a lightning discharge path regardless if you fly it over the cloud layer. 1 kg/km • 50 km • 9.8 m•s^-2 • 50 km = 24.5 MJ 10 MJ = kinetic energy of the armor-piercing round fired by the assault guns of the ISU-152 tank I think that's just about enough energy to cut just about any living thing in half. Maybe it work if the cable was made of spider silk or Kevlar.