These are essentially winged versions of "lifters" which were first produced in the 1960's. Their power per watt ratio is very low, so they may not be very usef

These are essentially winged versions of "lifters" which were first produced in the 1960's. Their power per watt ratio is very low, so they may not be very useful. Also, they need the surrounding air to generate ions and therefore cannot reach high altitudes where the atmosphere is very thin.