Gyro 2000 530Z Ikenga
The modern gyroplane is one of the most popular forms of sport aircraft. David Gittens, a gifted artist, inventor and industrial designer, built the Ikenka gyroplane as a safe, easy-to-fly, and affordable aerial platform for crop spraying and transport in developing countries that lacked a suitable aviation infrastructure. While this idealistic vision succumbed to the harsh realities of the aviation industry, Gittens' Ikenga illustrates that independent designers can still make important contributions to aircraft design in a field dominated by large government-sponsored corporations.
A gyroplane is an aircraft that derives most, if not all, of its lift from the unpowered autorotation of a horizontally mounted rotor or rotors. Unlike a helicopter, an engine does not drive the rotor blades while the aircraft is in flight. Instead, the resultant of the lift and drag forces act to pull the blade forward in rotation while also creating lift - the same effect that turns the sails on a windmill. This state of autorotation is only possible with a sustained airflow through the rotor disc, with the air moving from below and in front of the rotor to above and behind it. The gyroplane requires some propulsive force to maintain sufficient speed to sustain autorotation and hold altitude. In most early gyroplanes, an engine driving a tractor propeller supplied the necessary force. If the pilot reduced throttle while flying, the rotors would begin to slow and the gyroplane would descend. The increased airflow of the descent allowed the rotors to continue in autorotation and maintain the blades in an unstalled condition - even without the forward pull of the propeller. Although the pilot still had to maintain some forward motion for a landing flare-out, and to maintain airflow over the control surfaces, it allowed for unpowered and near vertical descents ending in a very short landing rollout. This was an excellent safety feature in case of engine failure. Without a powered rotor, gyroplanes are incapable of hovering, though later designs did include rotor spin-up mechanisms that allowed near-vertical "jump" takeoffs.
The modern gyroplane evolved from a precursor of the helicopter into a popular sport aircraft. The short take-off and near-vertical landing capabilities of the first gyroplanes, the Autogiros pioneered by Juan de la Cierva in the early 1920s, made the aircraft a popular attraction at air shows. However, high cost and limited payload limited their use as commercial or military aircraft. By the mid-1940s the superior performance and load-carrying capabilities of commercial helicopters rendered the Autogiro obsolete and the type almost completely disappeared until Igor Bensen popularized his line of Gyrogliders and Gyrocopters in the late 1950s. These were inexpensive, easily stored, and transportable personal aircraft used for recreation. While many of the gyroplanes produced in last twenty years of the twentieth century resembled Gyrocopters, there were some novel attempts to move away from the conventional pusher configuration of the earlier sport designs.
Born in 1939, David Gittens pursued his artistic vision through both conventional and unconventional mediums. While he expressed himself though drawing, graphic design, and painting, he also shared his vision through architectural plans and the design of musical instruments and vehicular transport. His concepts for automobiles, boats, and aircraft incorporate ideas that are both creative and innovative. In the 1960s, he applied his graphic design and engineering skills to the creation of a sports car capable of 274 kph (170 mph) that incorporated features such as closed-circuit television and rotary windshield wipers. In 1965, he encountered Wing Commander Ken Wallis who had considerable success in adapting the Bensen series for the British market and who had gained notoriety by flying in a James Bond movie. The meeting was an inspiration for Gittens to formulate his own reconception of the modern gyroplane.
In the early 1980s, after nearly ten years of research, Gittens began to design his own gyroplane, but unfortunately, he had little aeronautical engineering experience. He enlisted the help of George Hinson-Rider, a retired aeronautical engineer along with experienced gyroplane builders and designers Bill Parsons, Ed Alderfer, Jerri Barnett and Martin Hollman. With the help of Canadian investors, they formed a company called Gyro 2000 to develop new gyroplane designs. The first effort, known as the Wind Dancer, built between January 1985 and July 1986, was a 120-horsepower Mazda rotary engine-powered single-seat gyroplane, which employed the pusher propeller configuration that had become typical for sport gyroplanes. It featured a sleek and stylized enclosed cockpit that was unusual for sport gyroplanes of the time. The aircraft was unveiled to considerable acclaim at the 1986 Oshkosh airshow - a Mecca for experimental aircraft designs, but never flew.
Unfortunately, the Wind Dancer was simply too expensive and complex to construct in kit form. Gittens rethought some of the design elements with a renewed emphasis on simplicity. His prototype for the new type was the Ikenga, which in the Ibo mythology of Eastern Nigerian refers to the mask that embodies humanity's "creative life force." The Ikenga differed from the earlier model primarily in the use of a tractor propeller, which offered improved cooling in hot climates and substantial increases in engine and propeller efficiency. An aerodynamic Plexiglas enclosure on the front of the aircraft protected the pilot, who sat motorcycle-style, from the onrushing airflow, bugs, and bird-strikes. A dependable liquid-cooled two-stroke 530Z Suzuki engine powered the Ikenga. Its innovative control system featured rudder pedals controlled by the pilot's heels and a cyclic stick that centered over the pilot's right thigh. Like the previous design, it had a tricycle landing gear, and a small additional fourth wheel to prevent tail strikes during takeoff and landing.
The rotor system was a standard McCutcheon Skywheel with a low rotor disc-loading that made the aircraft safe to handle, and allowed speeds of up to 201 kph (125 mph). The 57 liter (15 gallon) fuel tank gave the Ikenga a maximum range of 568 kilometers (353 miles). The strong, but light, chromoly steel tubing of the frame allowed Gittens to design a U-shaped mount for the rotorhead that also served as a roll-bar for the pilot. The fiberglass and foam-core twin rudders also kept the empty weight of the aircraft to a miniscule 136 kg (300 lb).
Gittens, still himself a neophyte gyroplane pilot, selected Mark Hallet, an experienced builder and pilot of Bensen-style gyroplanes, to act as test pilot. The first flights of the Ikenga occurred in June 1988 at Espanola Airport in Santa Fe, New Mexico. This site provided a rigorous testing ground for the aircraft since density altitudes typically ranged near 3,048 meters (10,000 feet). Hallet found that the Ikenga had excellent stability and maneuverability during all phases of flight, except at flight speeds under 37 kph (23 mph).
The tractor propeller, in addition to offering better engine and propeller efficiency, had the added benefit of giving novice pilots an effective attitude reference - something that most open-frame pusher gyroplanes lacked, which could lead to pilot-induced oscillations. Pilots of light gyroplanes must strictly avoid any negative-G condition that could result during an oscillation because the unloaded rotor could teeter into the rotor mast and disintegrate - a condition known as mast-bumping.
Gyroplanes typically incorporate a small pre-rotator motor or power-takeoff clutch to bring the rotor to near autorotation rpm before starting the takeoff roll, which eliminates the need for high-speed taxiing to accomplish the same task. Initially, Gittens left this feature off, and the Ikenga took nearly 137 meters (450 feet) of runway to take off. Once installed, takeoff rolls reduced to around 30 meters (100 feet). Takeoff speed for the Ikenga was 56 kph (35 mph) and would have enabled the aircraft to operate in many developing nations without efficient infrastructure, and the potential for humanitarian support became part of its marketing campaign.
During 1988, the combination of innovative design and good performance earned Gittens some of the most prestigious awards in the gyroplane community. These included the Grand Champion Prize at the Alberquerque International Airshow, the Best New Rotorcraft Idea Award at the Popular Rotorcraft Convention, and most notably, the Rotorcraft Reserve Grand Champion Award at the Oshkosh International Airshow. With the new recognition, Gittens and Gyro 2000 sought to further improve on the Ikenga design and prepare for production with an improved series - the Cygnus.
The Cygnus designs incorporated off-the-shelf components to reduce production delays and cost significantly. Based on Hallet's input, Gittens did away with the unusual control system of the prototype Ikenga in favor of a conventional configuration for the Cygnus. Further improvements included a steerable nosewheel and adjustable 3-bladed propeller.
In 1994, foreign certification issues and the lack of capital led Gittens to cease gyroplane development, though at the end of the century, he continued to visualize new designs. In the same year, he donated the prototype Ikenga to the National Air and Space Museum where it demonstrates that personal innovation and artistic expression still play a role in aircraft design.
