Vehicles known as "Flying Jeeps" were built and flown by the Piasecki Company and the U.S. Army and Navy in the early 60's. These Vertical Take-Off & Landing machines proved the basic viability of a ducted, dual-fan configuration. However they had limitations in controllability and payload capacity.

Such designs, created in the era of the 1960's, really did not have the technology needed to bring success. Present day, more modern attempts include various improvements such as an on-board computerized flight control (fly-by-wire). This simplifies the complexity of piloting the aircraft. Also the weight of the machine can be reduced by replacing heavy mechanical controls with electronic devices. Advanced composite materials make the newer vehicles lighter and stronger. As well, modern turbine engines can now be used that are significantly lighter and more powerful than those available in the 60's.