CarterCopter: a high-speed, low-cost helicopter
June 3, 2004 Man has dreamt of personal flight for thousands of years, and attempted to fly for almost as long. Leonardo Da Vinci got it right when he stated, "the bird is a machine that operates according to mathematical law" when designing his ornithopter five centuries ago, but it took another four centuries for us to get the basics handled well enough to break the shackles of gravity.
It is ironic indeed that the technology creating the greatest barrier to mass personal flight is that of the human being - we are too careless, too erratic and make too many mistakes to be given pilot licenses en masse. Though we appear quite accepting of the carnage on the roads, there would be a much greater toll if as many people flew their own planes with the same level of competence as they drive their automobiles.
With a century of powered flight behind us, many futurists regard an era of mass powered personal flight as inevitable within the next century, and some see it as a lot sooner.
NASA's Langley Research Centre has a Personal Air Vehicle Exploration program understanding and nurturing the technologies which will enable the next generation of aircraft and they are predicting mass adoption not much more than a decade from now. Their vision of the future is not that much different to the people who saw the cars of the thirties somehow growing wings - practical everyday four-seaters within the reach of normal people.
NASA's work has many facets, - the American Government regards the aviation industry as its won. Americans invented flight, and has owned a large slice of the aviation and subsequent aerospace industry ever since. But things started to go wrong for aviation a quarter century ago - in 1978 the U.S. General Aviation (GA) industry delivered 17,811 aircraft. In 1993, the number of aircraft delivered had fallen to 954, an all-time low.
Therefore, in 1994, NASA, in partnership with U.S. industry and the Federal Aviation Administration, began a new partnership to rejuvenate the technology base and revitalize the industry. The partnership, together with critical tort reform and an expanding economy, contributed to a bright new future for Aviation and in 1998, there were 2,220 aircraft deliveries accompanied by expanding employment and more student pilots.
The biggest single problem in having the population take to the skies is already well on its way to being overcome - there is no pilot more attentive, more suitable to the assessment of and immediate response to the complexities of flight than the computer, and all the work being done with Unmanned Aerial Vehicles at present is likely to significantly enhance the safety of mass flight. There are of course many barriers to mass flight beyond overcoming human suitability, one of the foremost being that how to get a flying machine into and out of the sky safely.
Launching an aeroplane requires a speed quite unsuitable for public roads, so unless we were to suddenly make room in our overcrowded suburbs for a local landing strip, the only answer is VTOL - vertical take-off- and landing.
Gizmo has looked at several such designs, such as the Moller Skycar and Millenium Jet's XFV, but both are struggling to find commercial success given their unconventional approaches. Great minds and heavenly budgets have been spent pursuing this dream and until now it has eluded all efforts.
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.
By October of 1994, Carter was wind-tunnel testing a 1/6 scale model with incredible results - the model reached a Mu of 8 (not .8) before it became unstable. These tests confirmed the viability of the Carter design but many years of research, development and testing went into the next full-scale prototype, which first took to the skies in 1998. Meticulous attention to detail and safety saw steady progress, building to a very public test in March of 2002.
During that test flight, the Carter Prototype, by then called the CarterCopter, achieved a Mu ratio of .87 without incident. In addition, it achieved a minimum rotor rpm of 115, a speed of 173 mph, and an altitude of over 10,000 ft msl (mean sea level).
This accomplishment immediately generated very strong interest in military and aerospace circles and within two months of the test flight, Carter was included in a grant with Northrop-Grumman for unmanned vehicle research and is under consideration for several other research programs.
Jay Carter Jnrs company is now Carter Aviation Technologies and holds twelve patents with another three pending and Jay Carter believes his technology can be used to manufacture VTOL hybrid aircraft with performance superior to the Osprey tiltrotor at a far lower cost, with his designs applicable to aircraft as small as two-seat commuters all the way through to commercial craft for 120 passengers.
Jay Carter Jnr is incredibly positive about the future of CarterCopter. "We are currently poised to break the Mu-1 barrier within the next one to six months, which we believe will prove that our technology can be used to manufacture hybrid rotorcraft capable of travelling at speeds of up to 500 mph and altitudes of 45,000 feet.
""This should enable licensees to build rotorcraft with performance superior to the Osprey tiltrotor at a far lower cost. We believe our technology is scaleable up to the size of a C-130 transport plane. Over $20 billion was spent on R&D to develop the Osprey, and total program costs now exceed $50 billion. We have recently initiated negotiations with top management at some of the largest aerospace firms in the world, including Northrop-Grumman, Boeing, Lockheed-Martin, and Sikorsky Aircraft.
"We are also entering into high level discussions with several branches of the U.S. military. The reasons for this interest are simple. CarterCopter technology should enable the construction of aircraft that cruise at high speeds and altitudes with excellent fuel efficiency, take off and land vertically, hover, and carry sling loads.
"Moreover, CarterCopter aircraft should be safer than both helicopters and conventional aircraft, and less expensive than helicopters. Our technology literally promises to transform the aerospace industry. Also, with recent developments in Afghanistan, the military has become much more interested in developing the capabilities provided by our technology."