A SHORT HISTORY

If we except Leonardo da Vinci drawings, the history of rotary wings goes way back. In 1784, Launois and Bienvenue, two French physicians, presented to Paris Academy of Science the model of "a device with propeller that could fly". On August 21, 1907, the Breguet brothers and professor Richet would test the first 4-rotor aircraft, that was able to hoover 1 meter above the ground. Sure, it could not really fly... yet !

Just after the first World war, a few pilots found that flying these strange fixed-wings machines could be somewhat dangerous, due to their incredible ability to stall and to kill their pilots.

Some of them decided to research aircrafts that could not stall at all - therefore making flight safer. We could name there in France Henri Mignet, whose "living wing" would prove to be a safe concept for conventional aircrafts.

But, in parallel, in Spain, Juan de la Cierva took another direction: he believed that a "rotating wing" would do the trick. And it did, indeed ! Juan would become, after many trials and prototypes, the founder of the gyrocopter aircraft category. He would cross the Channel in flight in 1928.


Cierva C-4

January 9, 1923 C-4 flight

Juan de la Cierva
(1895 - 1936)


Development of the gyrocopter continued between the two wars, both in Europe and the USA. During WWII - an often forgotten history - they saw active duty, for instance as the mean for calibrating British radars, or as trailed observers on German submarines.

In parallel, the development of the helicopter, which did not saw anything really flying until 1937, continued as well.

Mainly for psychological reasons, the helicopter would then take over the gyrocopter for a good decade - military and civils alike not really understanding how a free-rotating rotor could, much more safely than a powered one, ensure the sustentation of an aircraft.

Once past de difficult 1950's, when people started again to think about leisure and pleasure, the gyrocopter came back into further development. From the 60's to the 80's, the main improvements came from the USA, then from Europe, mainly Finland, Italy and France. Strangely, Spain somewhat forgot that De la Cierva was the finder of this aircraft.

In the meantime, many projects had been tried, ranging from leisure to transport gyrocopters. For transportation, none succeeded so far, such as the British Fairey Rotodyne. But more recent gyrocopters may change this with the time. The Groen Hawk 4 served during the Olympic games as observer, and the Carter Copter continues its development, and represents today the most advanced gyrocopter ever made with performances hard to match. Today, many official entitites use light gyrocopters in several countries.


Fairey Rotodyne

Groen Hawk 4

Carter Copter

The main use today of gyrocopters lies in the leisure market. Tens of thousands of pilots enjoy flying these rotating wings. The researches have made them extremely secure to fly, as these are the only aircrafts (except helicopters) that can safely land without engine on a place barely exceeding their length.

GYROCOPTER vs. HELICOPTER

One of the most difficult part to understand is how the gyrocopter differs from the helicopter. Basically, the gyrocopter has a simpler construction than the helicopter, with a simplified rotor.

On an helicopter, the rotor is powered, and ensures both lift and propulsion. The helicopter rotor is simply acting as a big variable-pitch propeller. As such, the air attacks the rotor from above, giving it its "nose down" attitude in flight (exaggerated in the drawing for demonstration purposes). The powered rotor accelerates the air mass towards the ground.


Flash animation: helicopter vs. gyrocopter

On a gyrocopter, the rotor is free (unpowered), and only ensures the lift. Propulsion is ensured by a conventional tractive or propulsive propeller. The air attacks the rotor from below, giving a slight "nose up" attitude. By fleeing trough the rotor, the air maintain its permanent rotation. This is a complex phenomenon too long to describe here.

This is known as autorotation. In an helicopter, autorotation only happens when engine quits. In a gyrocopter, autorotation is permanent, it is its natural way of flying, with our without engine.

To start the autorotation phenomenon, a gyrocopter will, when stopped on the ground before take-off, prerotates its rotor, until it reaches sufficient RPMs to ensure lift after a short roll. After that... it is automatic, and the relative wind / weight combination will ensure permanent rotation - therefore lift - for the aircraft, rotor RPMs varying automatically as needed to maintain the needed lift along all phases of the flight.

So the main differences between gyrocopters and other aircraft kinds are the following, for the same MTOW:

GYROCOPTER
HELICOPTER
FIXED WINGS / TRIKES
Cannot hoover Can hoover Don't try to hoover
Cannot take-off vertically Can take-off vertically Cannot take-off vertically
Cannot land purely vertically Can land vertically Cannot land vertically
 
Needs very short take-off strip Take-off strip not needed Needs a take-off strip
Needs its length to land Needs its length to land Needs a landing strip
 
Very little sensibility to turbulences Medium sensibility to turbulences Sensible to turbulences
Larger flight envelope than fixed wings Larger flight envelope than fixed wings Limited flight envelope
 
Easy to pilot Complex to pilot Rather easy to pilot
Excellent manoeuvrability Superior manoeuvrability Average manoeuvrability
 
Easy for maintenance Relatively heavy maintenance Relatively easy for maintenance
 
Less expensive than helicopter Rather expensive Slightly less expensive than gyrocopter
Needs more power than fixed-wing / trikes Needs a lot of power Needs less power than gyrocopter

From this comparison, it is easy to extract that, where the specific hoover and take-off capabilities of an helicopter are not needed, a gyrocopter will do the same job at only a fraction of the expense. Gyrocopter excel in the watch and camera-plateform areas, at a much lower cost than helicopters. And of course as leisure aircrafts.

The increase of power needed by the gyrocopter compared to fixed-wings / trikes comes from the fact that the free rotating rotor generates about 70% of the total drag of the aircraft - this being compensated by more power, only really needed for the take-off part of the flight.

The private gyrocopter pilot will enjoy very quiet ride in turbulent conditions, and will fly when his mates are stuck in the airfield's bar due to strong winds, with a manoeuvrability comparable to the one of an helicopter. A light two-seater gyrocopter can usually fly as slow as 40 km/h, and in excess of 160 km/h.

Of course, comparing gyrocopters to fixed-wings or trikes is difficult, as this is really a matter of taste: some prefer rotary wings, other prefer fixed- or flex-wings.

All what we can say is: if you have never tried it, just try with a professional gyrocopter instructor. You may find it addictive.

PILOTING A GYROCOPTER

In the table above, we state that piloting is easy. This in no way means that you can sit in one, and just take-off ! Just like with any other aircraft, you will have to take lessons, and learn to pilot it. Depending on your country, your Civil Aviation Authorities may request more than what we hint below.

But, due to the fact that the gyrocopter's controls are basically identical and often simpler than those of a conventional fixed-wing aircraft, a fixed-wing pilot will usually need something like 10 hours dual training to convert to gyrocopter. Someone with no prior flight experience will need the same amount of time as he would for learning to pilot a fixed-wing aircraft.

We now suggest that you take a deeper look at our Phenix, an aircraft manufactured in De la Cierva country, and a credit to his spirit.