CarterCopter: a high-speed, low-cost helicopter

Rotorcraft, which have been around for 80 years, have the strength of VTOL, but no-one has ever been able to successfully combine a rotorcraft's vertical take-off and landing capabilities of rotorcraft with the flight characteristics (aka speed) of fixed-wing aircraft.

Perhaps the only successful development in this area so far is the Osprey CV-22, which is being seen primarily as a military aircraft and is expected to be operational with the US Air Force Special Operations Command (AFSOC) by 2009 with 50 ordered for delivery by 2017.

The CV-22 combines the speed and range of a turboprop aircraft with the vertical takeoff, landing and hover capabilities of a helicopter. AFSOC is America's specialized air power.

Recognising that the economic impact of such a vehicle could be astronomical if a design could be developed for general aviation use, Jay Carter Jr. began to methodically approach the solution a decade ago. His background with gyroplanes, helicopters and in aeronautical engineering was a strong foundation for systems design.

Jay's certification as a private pilot gave him insight into general aviation concerns. His business background provided guidance in development for cost effective manufacturing of future aircraft.

The difficulty inherent in combining the rotor and fixed-wing technologies has always been to slow the rotor and yet keep it stable while transferring the aircraft weight from rotor to wings. The slower the rotor rpm, the lower the drag. A key parameter of rotorcraft flight is Mu, where Mu is defined as the ratio of the forward flight speed to the rotor tip speed. Normal helicopters fly at a Mu of less than .5, limiting their speed.

The most unstable flight condition occurs at approximately Mu-.75. Sustained extreme Mu flight at a Mu of 0.8 or higher was previously thought impractical if not impossible.

Carter's concept uses a rotor for vertical takeoff and landing and a small wing for high speed cruising. The design was created to combine the speed and efficiency of a fixed wing aircraft with the off-airport abilities of a helicopter, without the complexity of a tiltrotor aircraft and other vectored thrust aircraft such as the Harrier.

...continued