The FAA describes a "gyrodyne" as a "rotor wing" aircraft that powers its rotor for takeoff and landing, but en route, flies in autorotation, like a gyroplane, without power to the rotor. Forward thrust is provided by engine driven propellers. Being able to fly in autorotation gives the gyrodyne all of the advantages and simplicity of a gyroplane.

More than forty years ago, a British aircraft manufacturer, Fairey Aviation Company, Ltd., developed a revolutionary new aircraft called the Rotodyne. The Fairey Rotodyne was a 44 passenger "gyrodyne" which used rotorblade tip jets to power its rotor for vertical takeoff and landing and gave it the ability to hover. Following take off and acceleration to forward flight, the tip jets were shut down and the aircraft flew in "autorotation" as a propeller driven gyroplane for the remainder of the flight. This 200‑mph VTOL airliner was, in its day, the fastest way to get from downtown London to downtown Paris. If it existed today, even without modern improvements, it would still be the fastest, safest method of travel between those two city centers.

Groen Brothers Aviation, Inc. (GBA) has developed a plan that can rapidly bring the gyrodyne into the modern age. Implementing this plan would enable the design, development, production and delivery of safe, fast, vertical takeoff and landing, long range high payload rotorcraft. These aircraft will have the ability to hover and will be economical, reliable and easy to maintain. This can be accomplished using a tiny fraction of the cost and time that would normally be necessary.

Gyrodyne components and flight control systems can be incorporated into certain existing production high wing airplanes with only small modification to the airframe. The time and cost savings benefits of using an existing production airplane are possible because neither the airframe nor most of its systems will need to be designed, engineered, developed, structural loads measured, analyzed, tested, redesigned and engineered, tested again and then prepared for production. And, since the technology is simple, engineering risks are low.

Groen Brothers Aviation has also developed proprietary mission adaptive rotor blade technology. This technology allows GBA's rotor systems to be optimized for hover flight and then during transition from hover to forward flight it can change to be optimized for high speed. Load sharing between the rotor and the aircraft's fixed wing adds to the high speed capability of GBA's gyrodyne aircraft designs.

Using an airplane that is already in production also means that the production plan, materials management system and massive supplier chain, quality assurance system, tooling, and production line are already in place and do not need to be designed, developed and paid for again, nor will there be a production learning curve to overcome. The only components that will need this development are the tip-jets (which have no moving parts), rotorblades, rotor head, mast and flight control system. Since the airframe is suspended from the rotor exactly from where it is suspended from its wing, in‑flight loads to the airframe should be virtually unchanged.

This concept was successfully tested by Groen Brothers Aviation through modifying a Cessna Skymaster airplane. It's two piston engines were removed. The forward engine was replaced with a Rolls-Royce model 250 gas turbine engine, and the aft engine was replaced with a large clam-shell cargo door. The wings were clipped and the existing twin boom tail was inverted to give rotor clearance. The rotor system from one of GBA's Hawk 4 Gyroplanes was directly connected to the high wing attach points that were already carrying the Skymaster's fuselage. This conversion, using minimal assets, took less than one year from first conception to first flight. This aircraft demonstrated its exceptional stability and ease of flight, characteristic of a well designed gyroplane.

The same process would permit the quick and economical introduction of VTOL GyroLiners in the 19, 35, 50, and 75 passenger sizes. These runway independent airliners could provide safe and reliable regional point-to-point transport and alleviate the continued congestion of air travel systems, a topic of major concern for the airline industry as growth begins to return. Much larger gyrodynes can also be developed at a fraction of the cost of developing similar helicopters, vectored thrust aircraft, tiltrotor or tiltwing aircraft, even if the gyrodyne is entirely designed new from the ground up. This is so because of the elegant simplicity of the gyrodyne.