Golden Age Pioneers: Juan de le Cierva

Juan de la Cierva (21 September 1895 -- 9 December 1936) born in Murcia, Spain to a wealthy family, was a Spanish civil engineer and pilot. His most famous accomplishment was the invention in 1919 of the Autogiro, a type of aircraft that later came to be called an autogyro.
Juan de la Cierva started building aircraft as early as 1912, and in 1919 he started to consider the use of windmills or rotors as a means of sustaining lift at low speed, and possibly eliminating the risk of stalling altogether. Ironically, he was later killed in an airline accident attributed to a stall.

Before this could be satisfactorily achieved, Cierva experienced several failures primarily associated with the unbalanced rolling movement generated when attempting take-off, due to asymmetry of lift between the advancing and retreating blades. This major difficulty was resolved by the introduction of the flapping hinge. In 1923, Cierva's first successful "Autogyro" was flown in Spain by Lt Gomez Spencer.

In 1925 he brought his C.6 to England and demonstrated it to the Air Ministry at Farnborough. This machine had a four bladed rotor with flapping hinges but relied upon conventional aircraft controls for pitch, roll and yaw. It was based upon an Avro 504K fuselage, initial rotation of the rotor was achieved by the manual tension of a rope passed around stops on the undersides of the blades.

The Farnborough demonstration was a great success, and resulted in an invitation to continue the work in the UK. As a direct result, and with the assistance of the Scottish industrialist James G Wier, the Cierva Autogyro Company was formed the following year.

The Avro built C.8 which was basically a refinement of the C.6, with the more powerful 180hp Lynx radial engine, and several C.8's were built. The C.8R incorporated drag hinges, as it was found that the presence of flapping hinges caused blade oscillation in azimuth; giving rise to high stresses with the risk of blade failure, this brought on other problems such as ground resonance for which friction type drag dampers were fitted.

A predominant problem with the gyroplane was concerned with achieving initial rotor rotation. Several methods were attempted in addition to the rope and drum system, which could take the rotor speed to 50% of that required, at which point movement along the ground to reach flying speed was necessary, while tilting the rotor to establish autorotation.

Another approach was to tilt the tail stabiliser to deflect engine slipstream up through the rotor. The most acceptable solution was finally achieved with the C.19, which was produced in some quantities; a direct drive from the engine to the rotor was fitted, through which the rotor could be accelerated up to speed. The system was then declutched for the commencement of take-off run.

As Cierva's autogiros achieved success and acceptance, others began to follow and with them came further innovation. Most important was the development of direct rotor control, which was achieved initially by tilting the rotor hub and subsequently by the application of cyclic pitch, causing the blades to rise or fall at appropriate points in their rotation, thereby effectively tilting the rotor in the required direction.

The introduction of jump take-off was another major improvement in capability. The rotor was accelerated in fine pitch until the rotor speed required for flight was achieved, and then declutched. The loss of torque caused the blades to swing forward on angled drag hinges with a resultant increase in collective pitch, causing the aircraft to leap into the air. With all the engine power now applied to the forward thrusting propeller, it was now possible to continue in forward flight with the rotor in autorotation.

All the above features were brought together in the C.30, which was produced in quantity for civil and military use, the autogiros of the 1930's were looked upon as a wonder of their time, but it must however be emphasised that they were not helicopters, and were not capable of vertical take-off, landing or hover in still air, albeit that they could maintain very low speed and accomplish a near vertical landing into wind.

Having successfully created and flown his gyroplane in Spain, Cierva established his company in Britain, comprising of a design office and sales organisation, calling upon established aircraft manufacturers to produce his designs. A number of well-known British firms produced aircraft for Cierva including; Avro, Comper, De Havilland and Westland.

The importance of Cierva's work on rotors and the effect upon the evolution of the helicopter cannot be overstated, and is indeed recognised throughout the industry. In the process of creating the Gyroplane (Autogyro), Cierva established an understanding of rotor dynamics and control, which was applicable to all rotorcraft, and undoubtedly led to the realisation of the helicopter.

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[twinten]

Very interesting. Nowhere though does it mention forward speed which I estimate to be less than 60 MPH with terrible gass miliage. Imagine a long trip against 25 MPH headwinds. The rotor absorbed a lot of power. The inefficiency killed it.

[Bomberguy]

Better than you might think, here are the specs on the C.30:

Performance

Maximum speed: 110 mph (177 km/h)

Cruise speed: 95 mph (153 km/h)

Range: 285 mi (458 km)

Rate of climb: 700 ft/min (213.4 m/min)

[hackajim]

faster than an automobile in 1895, in the air, sounds like 2010 new age george jetson technology.

[visineish]

@Tenchu73 Claro, si yo estoy contigo.

[Tenchu73]

@quimet0021 Desde luego que razon tienes, España no sabe tratar nada bien a sus inventores, si hubieramos desarrollado los inventos de nuestros genios como han hecho los otros paises europeos ahora España estaria entre las primeras potencias mundiales, pero no si por envidia, desidia etc por lo que sea, aqui es imposible desarrollar algo. Isaac Peral, tambien murciano, era el padre del submarino moderno y tambien renegaron de su invento que podria haber contribuido a ganar la guerra de Cuba.

[Tenchu73]

@Afrocanuk The articulated rotor, is, the main base of the autogyro and helicopter, was invented by Juan de la Cierva

[Tenchu73]

@visineish una cosa es dibujar algo en un boceto y otra cosa es desarrollarlo completamente y hacer que vuele, que es lo que hizo Juan de la Cierva. De hecho el rotor articulado que vemos en los helicopteros de hoy en dia lo inventó y desarrolló el, y tiene mucho mérito porque incluso hoy en dia sigue siendo una maravilla de la ingeniera, muy compleja.

[visineish]

Amigos, el inventor fue Juan de la Cieva, la historia del Mallorquin es solo eso una historia mas, tambien se dijo que la Coca Cola se invento en Valencia y muchas otras Historias, lo del señor Mallorquin si lo hubiese inventado el estaria patentado, de verdad que ganas de engañar al personal.

[Alastor73]

@Palouito oye idiota, FARSANTE tu padre, aprende a respetar las ideas de los demas aunque no te gusten. Pere de Son Gall inventó algo con la intencion, pero nunca lo consiguió, el que lo consiguió fué Juan de la Cierva ... y cuando veas un autogiro y un helicoptero y veas su rotor articulado (la helice principal) te lo metes en tu puta cabeza.

[Alastor73]

@Palouito se hicieron muchos diseños de aviones, unos volaron unos pocos segundos y otros no volaron, pero los que hicieron volar al primer avion fueron ellos ¿lo vas entendiendo? y lo del rotor articulado que se te quede en la cabeza que eso lo creó Juan de la Cierva, y funcionó, el aparato pudo volar.

[Alastor73]

@Palouito vamos a ver, lo vuelvo a repetir: artilugios como el que hizo este señor mallorquin ya se habian hecho incluso algunos siglos atras, donde hubieron grandes inventores, pero Juan de la Cierva te guste o no fué el que lo hizo volar ¿o como te crees que vuela un autogiro y un helicoptero? gracias al llamado ROTOR ARTICULADO, esa es la base de que puedan volar y ese artilugio solo podia diseñarlo un ingeniero como Juan de la Cierva. Es como los aviones, antes de los hermanos Wright

[Palouito]

gente como tú hacen que seas un farsante. PERE DE SON GALL ES EL REAL INVENTOR DEL AUTOGIRO!!!