Autogyro

Like a helicopter , the gyroplane has a rotor to create lift, but the gyroscope rotates freely under the action of aerodynamic forces in autorotation mode. A free gyro rotor is possible in a simplified scheme, without changing the overall pitch . It creates only lift and in flight it is tilted back against the stream, like a fixed wing with a positive angle of attack . In a helicopter, on the contrary, the screw (together with the body) tilts in the direction of movement ^[1] , creating a lifting and propulsive ^[2] force simultaneously with the drive rotor . In addition to the rotor , the gyroplane also has a pulling or pushing marching propeller, which tells the gyroplane the horizontal speed .

The intermediate position between the gyroplane and the helicopter is occupied by the rotorcraft , which has a connected rotor drive from the engine and differs from the gyroplane in that it can use not only autorotation mode, but also helicopter flight mode. At high speeds, the rotor system of the rotorcraft acts in a manner similar to a gyroplane (in autorotation mode), providing only lift, but not traction. We can say that the rotorcraft combines the qualities of a gyroplane and a helicopter.

The first gyroplanes with a rotor without a swashplate were controlled using aerodynamic rudders , so the vertical landing was uncontrollable and was usually considered an emergency mode. Modern control systems for the inclination of the plane of the rotor (the sleeve has two degrees of freedom ) allow landing without mileage, since the controllability of the device does not depend on its air speed. To realize a vertical start (by jumping), it is possible to pre-spin the rotor with a zero pitch on the ground (from the engine), followed by disconnecting its drive and setting the working pitch of the screw .

Autogyros were invented by the Spanish engineer Juan de la Cerva in 1919 , his gyroplane C-4 made its first flight on January 31, 1923 .

The main development of the theory of gyroplanes was in the 1930s . With the invention and mass construction of helicopters, interest in the practical use of gyroplanes fell so much that the development of new models was discontinued. A new phase of interest in gyroplanes began in the late 1950s - early 1960s. At this time, Igor Bensen ^[3] In the United States , gyrocopters of their own design actively promoted - light single-seat simple gyroplanes, which were sold in the form of self-assembly kits and were affordable for a wide range of people. In addition, at the turn of the 1960s, three models of two-seater jump gyro gyroplanes were developed and received certificates in the USA and Canada :

• Umbaugh 18A (later known as Air & Space 18A )
• McCulloch J-2
• Buhl A-1 Autogyro
• Avian 2/180

Of these three models, the first two were mass-produced. Several devices of these models are still flying. Avian 2/180 was built in the amount of several prototypes of different configurations, but was not mass-produced. The only surviving (flightless) device of this model is now privately owned in California , and the owner changed its name to Pegasus.

Most gyroplanes cannot take off vertically, but they need a much shorter take-off run for takeoff (10-50 m, with a rotor predispersion system) than airplanes . Almost all gyroplanes are capable of landing without a run or with a range of just a few meters, in addition, these devices are able to hang in one place with a strong headwind. Thus, in terms of maneuverability, they are between airplanes and helicopters, somewhat inferior to helicopters and absolutely superior to airplanes ^[4] .

Autogyros, in some respects, are superior to airplanes and helicopters in flight safety . Loss of speed is dangerous for an airplane, as it falls into a tailspin . At loss of speed, the gyroplane begins to decline. In the event of a motor failure, the gyroplane does not fall, instead, it decreases (plans) using the autorotation effect (the rotor of a helicopter in case of engine failure also goes into autorotation mode, but this takes a few seconds and rotor speed, which is important during an emergency landing). The pilot can fully control the direction of descent using all gyroplane control systems. When landing, the gyroplane does not require a landing strip , which is also important for flight safety, especially when forced landing in an unfamiliar place.

The speed of a gyroplane is comparable to the speed of a light helicopter and is somewhat inferior to a light aircraft. In terms of fuel consumption, they are inferior to airplanes, the technical cost of an autogyro’s flight hour is several times lower than that of a helicopter, due to the lack of a complex transmission; theoretically gyroplanes are also more economical than helicopters ^[5] . Typical gyroplanes fly at speeds up to 180 km / h (a record of 207.7 km / h), and fuel consumption is 15 liters per 100 km at a speed of 120 km / h. Thus, in speed and economy, the gyro resembles a car with the difference that it moves through the air.

Another advantage is a wide view and much less vibration than in helicopters, which makes them very convenient for aerial photography , video shooting and surveillance.

The gyroplane also has a significant advantage over other types of light aircraft: it can fly even in strong (up to 20 m / s) wind.

Among the shortcomings of the gyroplane (compared to a light aircraft with equal engine power) can be called a significantly higher fuel consumption due to the large rotor resistance, as well as a number of dangerous modes inherent in this device: loss of pitch control (somersault) and sinusoidal oscillation, which led to a series of accidents of gyroplanes in 1970-2000.

Most gyros are single and double. There are three-seater models: the Russian Okhotnik- 3 gyroplane, manufactured by the Aero-Astra- Avtozhir research and production center ^[6] , and the A002 gyroplane, produced serially by the Irkut IAPO ^[7] . At a wind speed of more than 8 m / s it takes off, a run up to 15 m is needed in the calm.

The most massive in recent years have become autogyros of the German company AutoGyro . Since 2003, the production of these devices has increased rapidly and now amounts to more than 300 cars per year ^[8] .

Classification

According to the location of the propeller, gyroplanes are divided into 2 types: with a pulling screw (historically the first devices) and with a pushing screw (the most common at present). Advantages of the propeller scheme: better engine cooling due to propeller blowing and somewhat greater safety in the event of an accident with a bow stroke (in a scheme with a propeller in such an accident, the engine located behind the cockpit may fall forward and injure the pilot). At the same time, in the scheme with a pushing screw, the view from the cabin is better. Both schemes have other inherent advantages and disadvantages.

Special Properties

Some gyroplanes are capable of jumping off. In this case, the rotor blades are placed horizontally (in a small overall step), the screw is untwisted to revolutions exceeding the nominal flight, then its blades rotate in the flight step. Takeoff takes place vertically due to the accumulated energy of the propeller. The implementation of such a scheme requires a significant complication of the design of the rotor sleeve and the weighting of the blades, therefore gyroplane jump jumps are not common.

Many gyroplanes are equipped with pre-rotation of the rotor. In this case, the rotor spins up before the gyroplane starts to take off (via transmission from the main engine or from a separate drive). Pre-promotion significantly reduces the take-off take-off speed of the gyroplane, and in the headwind, take-off takes place almost "from the spot."

Developed by American enthusiast Jay Carter, the six-seater gyroplane CarterCopter with hopping take-off has a unique ability to slow down the rotation of the rotor at high speeds, while the bearing force is provided by a wing of small scope, the difference in the lifting force of the forward and backward blades becomes irrelevant. Due to this, it is possible to accelerate to speeds unique to the rotorcraft technology for 600 km / h. The first flight of September 24, 1998, the crash of June 17, 2005. The project was renamed Carter Personal Air Vehicle.

• The device is on average much cheaper than light aircraft and helicopters;
• Driving a gyroplane is simpler than an airplane and a helicopter;
• One of the safest aircraft, which determines its following features:
  • not subject to corkscrew ;
  • able to make a soft landing with the engine off;
  • small requirements for the landing site;
  • much less sensitive to thermal flows (compared with a hang glider and a paraglider );
  • less sensitive to turbulence (compared to aircraft).

The main disadvantage of gyroplanes is the lower efficiency of using the power plant, which is why, with equal flight weight and speed, the gyroplane needs a more powerful engine than an airplane or a deltlet .

A gyroplane with a two-bladed bearing rotor has several specific dangerous flight modes (unloading the rotor, somersault, autorotation dead zone, etc.) that cannot be allowed during flight to avoid a fall. Flip-flop is characteristic mainly for devices with a center of gravity incorrectly located relative to each other and a propeller thrust vector, as well as with an underdeveloped tail.

Flying in a gyroplane in icing conditions is a great danger, since when the rotor ices, it quickly leaves the autorotation mode, which leads to a fall.

The first Soviet gyroplane KaSkr-1 "Red Engineer" developed by N.I. Kamov and N.K. Skrzhinsky took off on September 25, 1929 . The gyroplane was piloted by I.V. Mikheev, and its creator N.I. Kamov was in the rear cockpit.

After that, a number of models were created at Kamov Design Bureau . The autogyro A-7 passed flight tests for use in aircraft chemical operations, including pollination in the foothills of the Pamirs .

In 1936, at a meeting of a special commission under the Politburo of the Central Committee of the All-Union Communist Party of Bolsheviks, which oversaw the creation of the first drifting station in the Arctic Ocean , options for the delivery of polar explorers to the ice were discussed. The son of V. Chapaev Arkady Chapaev (1914-1939) proposed to make gyroplanes. They should be hung under the wings of a heavy transport aircraft. The idea did not pass. ^[9]

Currently, several groups and enterprises are engaged in the development of gyroplanes in Russia:

• Behind the Clouds - Gyro-GT Model
• AeroKazachok - model Cossack
• IAPO - model A002 Irkut
• Aero-Astra - Hunter model
• Twister Club - Twist Model
• AviaMaster - “Inspector” model
• “MRT Group of Companies” is Xenon brand gyroplane for tourist flights, patrolling gas and oil pipelines, monitoring forest fires, border protection ^[10] .

In September 2011, during the strategic exercises of Center-2011 at the Chebarkul training ground , co-owner of MRT-AVIA Roman Putin made a presentation of the latest gyroplane model to Dmitry Medvedev ^[11] .

• Bratukhin I.P. Autogyros. Theory and calculation . - Gosmashmetizdat, 1934 .-- 110 s.
• Zhabrov A.A. Autogyro and helicopter . - 2nd ed . - The Central Council of the OSOAVIAHIM of the USSR, 1939.
• Rotorcraft Flying Handbook, FAA Manual H-8083-21 , Chapters 15-22. Washington, DC: Flight Standards Service, Federal Aviation Administration , US Dept. of Transportation, 2001. ISBN 1-56027-404-2 .
• Andreas G. Stuetz. Weltflug: The Gyroplane Dream . - Createspace Independent Pub, 2013 .-- ISBN 978-1-4937-6094-7 .

• Russian-language forum on gyroplanes (rus.)
• Russian-language forum on gyroplanes (rus.)
• English-speaking forum on gyroplanes - theoretical and practical information
• Video gyro workshop for beginners (Russian)
• A. Shcherbakov, “Dancing Twist?” - an article about the advantages and disadvantages of gyroplanes.