Future land based vehicles will likely be powered by electricity. Eventually, airplanes, and then rotorcraft, will probably follow suit. Unfortunately, it has taken rotorcraft seven decades to get from being just airborne with a hydrocarbon power source to the 50/50 empty-weight to payload ratio that can be achieved today. How long will it take before an electric motor can cause a rotorcraft to hover and how many decades more before this electric-powered rotorcraft can achieve today's 50/50 empty-weight to payload ratio?

IMO, there are two primary requirements that are necessary to achieve the above goals. The first is the development of extremely efficient electrical storage and electro-mechanical conversion devices. The costs to achieve these objectives are far beyond the abilities of the rotorcraft industry, however other industries are working on this.

The second requirement is exclusively the domain of the rotorcraft industry. This requirement entails the optimization of the thrust to power ration of rotors. Or to phrase it in differently, it is essential that Lift/Drag be significantly improved.

Again IMO, there are two primary requirement that the rotorcraft industry must achieve. The first one is easy. The second one will take money and engineering. Both require a commitment on the part of farsighted management to build a better 'mousetrap'.

The first is to utilize a rotor configuration that gives the lowest possible disk loading within the restraints of the craft's mission profile. For low disk loading nothing can surpass the twin main-rotor Side-by-side configuration. However, to better suit the specific requirements of the craft it will probably be more appropriate to bring these two rotors closer together and utilize the Interleaving configuration.

The second is to distribute this disk loading as efficiently as possible about the area of the total disk area. In other words, the objective is to control the angle of attack at as many discrete locations (radius * azimuth) as is possible. For this there is the need to replace the one per rev flight-control with a control that has a considerably higher frequency. And, there is the need to have relatively independent zones along the span of each blade. The ultimate technological details and components may come from outside the rotorcraft industry, however, this industry can start to develop and implement much of the foundations and basics now.