Cierva C.7
| Cierva C.7 | |
|---|---|
| Type: | Gyroplane |
| Design country: | |
| Manufacturer: |
Jorge Loring Martinez |
| First flight: |
November 15, 1926 |
| Number of pieces: |
1 |
The Cierva C.7 (also Loring C.VII ) was a gyroplane of the designer Juan de la Cierva , from the mid-1920s, a copy in Spain by Jorge Loring was built.
history
Although from 1926 the further development of the Cierva gyrocopter mainly took place in Great Britain, the Spanish Air Force ordered two more models in Spain with the C.7 and C.12 . The construction was carried out by Jorge Loring in his Carabanchel plant, which was located near the former airfield Cuatro Vientos . Today the company Aeronáutica Industrial, SA (AISA) is based here. He used the fuselage of a Loring T-1 mail plane with a 300 hp water-cooled Hispano-Suiza engine as the starting design . With this engine, the C.7 was the most powerful gyroplane ever built. A four-blade rotor equipped with flapping joints provided the lift. Ailerons on stub wings were provided for steering around the roll axis. Initially, a grinding wheel chassis with two wheels on the left and right with their own axles on the main chassis was used.
The first flight of the machine, with JL Ureta at the controls, took place on November 15, 1926 shortly after the return from the air show in Madrid, which took place from October 27 to November 7, 1926. After a rotor blade fracture occurred in February 1927 on the Cierva C.6, which was built in England , probably triggered by the fatigue fracture of a blade root due to the lack of flexibility of the blades in the plane of rotation, the gyroplanes manufactured there were given an additional vertical joint in addition to the flapping joint . The Spanish C.7 also received this modification and at the same time the four-wheel chassis was replaced by a conventional two-wheeled wheel chassis. The English pilot Reginald Truelove carried out the tests in May 1927 in this version.
Although the Spanish Air Force had ordered two copies of the C.7, only one machine was completed. Cierva himself also made many flights as a passenger on the C.7 in order to better observe vibration problems with the wire tension between the rotor blades. The reason was found to be that the horizontal and vertical rotor joints did not have a common axis of rotation. In order to keep the vibrations triggered by this within tolerable limits, lengthy development measures, mainly carried out in England, were necessary. As a result, the rotors of later prototypes received appropriately tuned vibration dampers.
See also
literature
- PT Capon: Cierva's first autogiros Part 2 . In: Airplane Monthly, May 1979, pp. 238-239
- Arthur WJG Ord-Hume: Autogiro - Rotary Wings Before the Helicopter , Mushroom Model Publications, 2009, ISBN 978-83-89450-83-8 , pp. 71-72
Individual evidence
- ↑ Ord-Hume, 2009, p. 71. Capon, 1979 gives different information