Full composite body gyroplane

(Published on January-February 2009 – JEC Magazine #46)

The autogyro, or gyroplane, is a largely unfamiliar type of aircraft, a sort of missing link between the aeroplane and the helicopter. Like a helicopter, it is a rotary wing aircraft, but it flies neither like a helicopter nor like a fixed-wing aircraft. Here, there is no tail rotor. It is not particularly difficult to fly; it is easier to handle than a helicopter and in various respects it is easier to pilot than a “regular” aeroplane. All the same, specific flight training is required.

Historic overview

The term “autogyro” defines an aircraft that is equipped with a non-enginepowered rotor. Autogyros are also known as gyroplanes, gyrocopters, or rotaplanes. The autogyro was invented by a Spaniard, Juan de la Cierva, in 1919 with a view to eliminating stall (when an aeroplane’s speed is insufficient the aircraft will fall abruptly, since the lift provided by the wings is no longer sufficient). In the years that followed, he made many improvements to his “Autogiro” of 1923. His work also made an important contribution to the development of the helicopter. In the 1950s, Dr Igor Bensen introduced the propulsion engine, along with the rigid coupling of the twin blades. He dubbed this new ultra-light aircraft of simple design the “Gyrocopter”. The autogyros that we see today continue to be built along the same lines.

Advantages and limitations

Appropriately enough, since this was precisely what they were design ed for, gyroplanes do not stall. They simply lose altitude slowly at very low speeds, in similar fashion to the autorotation of a helicopter’s blades that allows it to land without engine power. The autogyro can therefore fly slowly.

On an aeroplane, spin occurs when one wing stalls while the other continues to have lift. Since the gyroplane cannot stall, nor can it enter into a spin. It can be dangerous with this type of aircraft to take tight parabolic flight paths as is done with so-called “Zero G” aircraft that simulate weightlessness. It should also be noted that starting up the rotor on takeoff can be a somewhat delicate operation. Yet the many aforementioned advantages, along with the very short landing and take-off distances, all testify in favour of this aircraft, which remains very much a UFO in the eyes of the general public.

The prototype

The fuselage with retractable nose wheel is made entirely out of carbon and aramid. The prototype was made with prepregs. In production, the aircraft will be manufactured via infusion. The rotor head and main blades are for the moment made out of aluminium, as FD Composites has preferred to concentrate on the airframe and use already-certified mechanical parts. Once the aircraft has received type approval, FD Composites intends to manufacture the blades out of composites and have them type-approved in turn.

Towards certification

The maiden flight of the Arrow Copter AC 10 took place in November 2008: the last stage before marketing and certification…