AEROMEDIA
The Italian Aerospace Information Web
by Aeromedia - corso Giambone 46/18 - 10135 Torino (Italy)

Some Significant Events Regarding the Autogyro Saga

Juan de la Cierva, born on September 21, 1895, in Murcia, Spain, was the man who invented the autogyro. He was interested in flight as a teenager and experimented with gliders with his friends. After receiving his aeronautical engineering degree, in 1918 he built the first trimotor airplane. Its crash in 1919 after a stall convinced him that aviation safety called for a stall-proof aircraft.
He began experimenting with rotating-wing aircraft in 1920. His first attempts with rigid rotors were unsuccessful, leading him to the idea of moveable blades. These were mounted to the hub of the rotor on hinges so they could flap. This simple expediency equalizes lift on the advancing and retreating blades of the rotor by allowing the blades to remain in roll-equilibrium, rising as lift increases then lowering as lift diminishes.
His first successful flight with the autogyro took place on January 9 1923. The La Cierva autogyro was equipped with a conventional propeller for forward flight and an articulated, or hinged, free-rotating rotor providing the lift.
This is the real secret of the autogyro, where each hinged blade rises or falls automatically during each revolution, balancing the roll component of the blades without any requirements for control inputs by the pilot. But this machine still needed a take-off roll, and could neither take-off nor land vertically. For many years machines with these characteristics had been studied and designed, but with little practical success – until 1936 when Focke-Wulf of Germany produced their Fw 61 twin rotor aircraft - the first truly functional helicopter.
Despite being considerably more complex and expensive to operate, the helicopter would most likely have completely replaced the autogyro during the years which followed WW2 if it were not for Igor B. Bensen. Born in 1917 in Rostov, Russia, Bensen had gained a mechanical engineering degree from the Stevens Institute in Hoboken, New Jersey in 1940 and went to work for General Electric.
In 1944, he became responsible for GE's helicopter research and development department. During this time he was became familiar with the Hafner AR III Rotochute and the Focke Achgelis Fa 330 Bachstelze (Water Wagtail) - a towed autogyro.
In 1953, he founded the Bensen Aircraft Corporation in Raleigh, North Carolina. By 1954, the company was selling plans for the unpowered B-6 Gyroglider. It looked a lot like the Hafner Rotochute, and was designed using 3/8 inch water pipe and plywood - things that people could easily find at their local hardware store. His next model was the B-7 Gyroglider, constructed from Reynolds "Do-it-yourself" aluminum.
The B-7M was Bensen's first powered Gyrocopter and used a Nelson H-59 engine. The round tube frame was a little difficult for homebuilders to plug and drill accurately, so the B-8 frames were in 2 x 2 tubing - much simpler to work with. Customarily the B-8M used the McCulloch engine that had been originally designed for small military target drones.
Over the years, the Bensen Gyrocopter became the most purchased of all the homebuilt aircraft plans. The Bensen Aircraft Corporation was the first gyroplane manufacturer to offer their aircraft in kit form and was among the first to do so in any type of Sport Aviation.
Jukka Tervamäki, born in 1935 in Punkalaidun, Finland, is amongst the promoters of the autogyro revival. While in high school in 1954, Jukka saw an article on the Bensen Gyroglider in a “Life” magazine and came across a Bensen advertisement for gyrocopter kits in the magazine “Popular Mechanics”. This led him to start dreaming of his own autogyro. He concentrated on his studies at Helsinki Technical University in rotary wing aircraft and later bought a Bensen B-7M rotor head for his first machine, the JT-1. This machine flew in 1959.
Some 6 years later he had a more ambitious project under way, the ATE-3 autogyro which flew for the first time in 1968. This development also included the world’s first composite autogyro rotor blades and an extensive study of gyro stability with a horizontal stabilizer.
Finally in 1969 he designed the JT-5 single-seat autogyro which, when it flew, became world famous after many stories in world experimental aviation magazines. It was the first truly modern gyroplane, with enclosed cabin and many composite parts. The tail unit included large central fin and rudder and two small fixed planes at the tips of the stabilizers. Several enthusiasts around the world bought the JT-5 drawings to buld their personal gyro.
Soon after, Jukka Tervamäki shifted his interest from autogyros to motorgliders and started his next project, the JT-6 motorglider. He then decided to sell his JT-5 autogyro and got many offers from people in various countries. Vittorio Magni from Italy made the best offer and found himself the new owner of the JT-5.
Born near Milan in 1938, Vittorio Magni gained his initial technical knowledge in 1956 at Agusta working in the transmission, engine and airframe departments. In 1962 he was recruited as a specialist in the Helicopter Division of Montedison, acquiring experience in crop spraying and aerial disinfestations. In 1964 he was engaged with Elitaliana, a Milan/Linate based air work company set up by Commander Enzo Flammini and specialized in crop spraying.
In 1967, thanks to his wide rotorcraft experience, Magni collaborated with Silvercraft, a brand new company created to build the new SH-4 light helicopter. At Silvercraft, he was appointed Flight Line Leader and, in the same period, he obtained a helicopter pilot’s license. In the same year he bought the plans of a Bensen B-8M gyroplane from the U.S.A. The result was one of the first autogyros to fly in Italy.
As a matter of historical interest, two gyrocopters had been brought to flying status by amateur builders, in Turin, some years earlier. The very first one was a free interpretation of a Bensen B-7M, built by a group of enthusiast pilots headed by Commander Ferruccio Vignoli, at that time Director of the Turin Aero Club Powered Flight School. The second was a more orthodox B-8M manufactured by Agostino Murchio, an early Italian homebuilder and also a member of the Turin Aero Club. In 1962, around these individual enterprises, the "STAR - Sezione Torinese Ala Rotante dell’Aero Club Torino” (Rotary Wing Turin Section) had been established. So it was no surprise to anyone when Vignoli’s machine was mock-registered “I-STAR”, in honor of the above mentioned “Sezione”. This specially built autogyro, powered by a 74 hp McCulloch O-100-1 “target drone” four-cylinder two-stroke engine driving a two-blade wooden propeller, had a short but eventful life. As early as 1963, before the installiation of the engine and towed by a car, the autogyro underwent some stability tests. After the very first powered test hops it was re-registered with the similarly fake “I-SART” markings. Unfortunately, after a further number of encouraging flights, during a ground run the rotor cut through the imposing fin of the gyroplane, which was then prudentially stored, becoming a relic for posterity.
In the meantime, Murchio’s Bensen B-8M was readied for flight testing, receiving the registration “I-FRUI” (“frui” means “bolt” in the Piedmontese dialect). Commander Vignoli, fresh from his limited but intense autogyro experience, appointed himself as test pilot, only to soon escape unhurt from a disastrous landing accident. From that day on, no further autogyros were seen at Turin/Aeritalia airport, until recently, with Aeromnia’s ELA 07 Cougar.
The registration marks of both these early machines were “unofficial” since in Italy, at that time, experimental homebuilt aircraft were not contemplated by the RAI (the National Technical Aviation Authority), and consequently they were technically “illegal”.
As a follow-up to this short account of Turin’s gyrocopter history, it is worth mentioning that Commander Vignoli, on August 4, 1994, presented the relic of I-SART to the Turin Chapter of GAVS (the historical aircraft restoration group). This non-profit association, assuming it finds a sponsor, will proceed to complete the static restoration of this historic aircraft. At the moment, the McCulloch engine is undergoing functional restoration and the missing propeller has been rebuilt from scratch.
As previously mentioned, during the early 1970’s of the past century, Magni bought the JT-5 from Jukka Tervamäki. As part of the purchase, he also got all the tooling, moulds and composite rotorblade know-how. However, when returning to Milan, he affirms that during a stop at a service station, a bag full of notes/drawings and his luggage were stolen. Accordingly, he had to rely on his memory and on the copies that Jukka was able to send him. After a rapid reassembly, the JT-5 was redesignated Magni MT-5, received "provisional" registration as I-MAGN and, in 1973, took part in the very first Meeting of the Club Aviazione Popolare (the Italian Experimental Aircraft Association) and in few successive editions of the “Raduno del CAP”. In this period, the Magni’s machine was sporting the “Eligiro” logo.
In 1977, Magni set up a small company named VPM, based in Cavaria (Lombardy), for the design and development of single and two-seat autogyros based on the JT-5 rotor head and blade design.
In 1980, Magni asked Jukka Tervamäki to design a new two-seat autogyro. The machine - with enclosed cabin, side-by-side accomodation, twin-tail and 150 hp Lycoming engine, got the project name MT-7 (Magni-Tervamäki). The Finnish designer did all the calculations and the general design, delivering the blueprints to Vittorio Magni, who was responsible for the detail design. The new machine - redesignated VPM S-2 - was completed in 1984, receiving registration marks I-VILU.
VPM’s first commercial success came in 1986, when the company signed a contract with CENEMESA (Constructora Nacional de Maquinaria Eléctrica) of Spain, for the licence production of two gyroplane models: the single-seat MT-5 and the two-seat S-2 (MT-7), both powered by Arrow engines.
In 1996, VPM was renamed Magni Gyro, being mainly engaged to improve current gyrocopter models and to develop new models. A department for manufacturing composite parts was also set up, in order to satisfy the increasing demand from aeronautical companies such as Agusta and Aerea.
After its initial years in Cavaria, Magni Gyro underwent its first expansion in 2000, when it moved to a 900 sq.m building in Besnate, a small town near Varese. In January 2008, a new, 2,000 sq.m building was added, suitable for the manufacturing of 6 gyroplanes per month, giving an annual production of approx 60-70 units. The quality in design and manufacturing of Magni Gyro sees the Italian company at the top end of the market; their products, including the M-16 Tandem Trainer, the M-22 Voyager and the M-24 Orion two-seaters, are considered as benchmarks for the sector.
In addition to Magni Gyro and ELA Aviación, a Spanish manufacturer with an outstanding rotor design, there are many enterprises active in the autogyro sector. They offer, with fluctuating results, a plethora of gyrocopters in assembled, kit or plan forms. The long list of companies includes AAT – Advanced Aircraft Technologies (Austria); Air Command (USA), Air Copter (France); Air Bet (Spain); Aircraft Design (USA); Astra Aero (Russia); Aerso Aviation (France); Autogyro (Germany); Barnett Rotorcraft (USA); Bauer Avion (Czech Republic); Butterfly (USA); Carpenterie Pagotto (Italy); Carter Copters (USA); Celiar Aviation (Poland); Chayair (South Africa); Eben Mocke (South Africa); GBA - Groen Brothers Aviaton (USA); Gyro-Kopp-Ters (USA); Gyrotec (Germany); Layzell Gyroplanes (UK); Little Wing Autogyros (USA); Merlin Autogyros (UK); Michel Delluc (France); Midwest Engimeering & Design – Flitplane (USA); North American Rotorwerks (USA); Ralf Taggart (USA); Rotor Flight Dynamics (USA); Rotor Hawk Industries (USA); Rotortec (Germany); Schröder Gyrocopter (Germany); Sport Copter (USA); Star Bee Gyros (USA); UFO - Ultimate Flying Options (New Zealand) and Vortech (USA). The latter is still selling the plans to build the Bensen B-19 Glider and the B-20 Kopter powered by a 35 hp engine. In addition, many individual amateur builders, all around the world, have designed their own personal gyroplane. In this category, one of the most significant is the original EJM-002 two-seat cabin gyroplane, designed by sport pilot Jean Marie Enfissi of France, and flown for the first time in 2004. It is just one example of the wide interest and enthusiasm which today characterizes the magic world of the gyroplanes.

In the picture: AVRO Type 671 (c/n 753) I-CIER autogyro at “Leonado da Vinci” Science and Technology National Museum in Milan, Italy, photographed during the 1970’s. It is a Cierva C.30A model manufacured under licence in Great Britain in the 1930’ and initially registered G-ACXA. The aircraft was later bought by the Italian “Regia Marina” (serial MM30030) for evaluations which led to no orders. The possible use of autoyros aboard Italian warships unleashed a competence conflict with the “Regia Aeronautica”. In 1941, it was bought by Vittorio Bonomi of Milan, receiving the civil registration I-CIER. Having survived WW2, the autogyro had a further lease of life, flying till 1948. In the ‘Seventies, it was restored and presented to the Milan’s museum. (Luigi Perinetti Postcard Collection)

(Aeromedia with contributions from Jukka Tervamäki web-site: http://www.icon.fi/~jtki/)