Cierva C.30

Cierva C.30
C.30A (Plant No. 726)
Type:	Gyroplane
Design country:	United Kingdom
Manufacturer:	AV Roe and Company
First flight:	1934
Number of pieces:	78 (66 civil + 12 military) 65 as license production in Germany and France

C.30A G – ACWH at a flight demonstration at the Paris Aero Salon in 1934

The Cierva C.30 (also Avro 671 ) was a gyroplane built by AV Roe and Company as a licensee of the Cierva Autogiro Company in the mid-1930s in Great Britain .

history

development

The hanging direct control stick in a C.30. The pilot sat in the back seat.

In early 1934 Avro received a license to build the Cierva C.30, a two-seat gyroplane powered by a 140 hp Armstrong Siddeley Genet Major IA. The rotor system was also to be built by Avro in Manchester . Development base for the first C.30 (coding G-ACFI), which in Hanworth by the National Flying Services was built, which was Cierva C.19 Mk. V . This was followed by a C.30P prototype (G-ACKA) built by Airwork in Heston and three C.30P pre-series machines (G-ACIM, ACIN and ACIO) built by Avro in Manchester.

The C.30 introduced the direct control flight control system, first tested in the C.19 Mk. V, into series production. With the C.30, Avro also carried out research on direct launch - i.e. without a previous take-off run. For this purpose, the Auto-Dynamic rotor head, which was used experimentally for the first time in the Weir W.2, was built into the G-ACWF and presented to the public on the Hounslow Heath airfield on July 23, 1936. The swivel joints of the rotor were inclined here and had no friction dampers in order to enable a very quick adjustment of the angle of attack and thus a jump start. For this purpose, the rotor was set in rotation beyond the actual speed of the autorotation before the start and then the kinetic energy stored in the overspeed of the rotor was converted into an upward movement by a sudden collective change in the angle of attack of the rotor blades from the zero position.

Military production

Restored C.30A with the markings of a Rota I used in the Second World War for the calibration of radar systems

One of the first orders came from the Air Ministry , which on February 14, 1934 ordered ten (later twelve) machines for test purposes in the field of army support. The airframe was given the military designation Rota I , while the engine Civet I was called. The delivery took place between August 24, 1934 and May 23, 1935 to the School of Army Co-operation . The requirements were summarized in the Air Ministry Specification 16/35, which was created in 1935 adapted to the existing machine. At this point in time, it was also retrospectively given the factory name Avro 671 .

The first Rota (RAF serial number K4230) went to the Directorate of Technical Development in 1934 , which they passed on to the Airplane and Armament Experimental Establishment at RAF Martlesham Heath on February 5, 1935 for testing . There the machine then received externally attached air bags for deck landing attempts on the HMS Furious and later on the HMS Courageous . K4296, the first of the two Rota I additionally ordered, received metal floats and flew it for the first time on April 15, 1935 from the River Medway .

At the beginning of the war, most of the civil C.30A still in England were stored in Hanworth and Hamble . In early 1941, the Autogiro department of No. 74 (Signals) Wing picked up six of them, which were used together with four remaining Rota I and seven other civilian C.30A for calibration flights of the radar systems installed on the coast. In February 1942 the unit was moved to No. 1448 Flight and in June 1943 in No. Renamed 529 Squadron.

Civil production

Civil production and export comprised 66 copies of the C.30A, which were distributed through the Cierva headquarters in Hanworth. Between 1935 and around 1938 the majority of all C.30s were registered in Great Britain, but after that they lost their popularity there. 16 formerly British registered machines were sold on to Australia, France, Germany, Italy, the Netherlands, Poland and Switzerland. Direct export deliveries were made to China, India, Lithuania, Russia and Australia.

License production

In France, the C.30A was built by Lioré et Olivier as the LeO C.30 with a Salmson 9NE . Focke-Wulf built 40 C.30A with a Siemens engine as Focke-Wulf Fw 30 .

Versions

C.30

first prototype

C.30P

another prototype and three pre-series machines

C.30A

civil series variant. Changed chassis with larger track width and more powerful engine compared to the C.30P

Avro Rota I.

12 copies of the military series variant, at the beginning of 1941 six C.30A were additionally put into service as Rota I.

Technical specifications

after Ord-Hume

Parameter	C.30	C.30A	C.30A Rota (seaplane)
crew	2
length	6.10 m	6.00 m
Span of the wing	without wings
Rotor diameter (three-blade rotor)	11.29 m
Rotor speed	180 to 210 min -1
height	3.38 m
Empty mass	554 kg		679 kg
Max. Takeoff mass	817 kg	863 kg	948 kg
Top speed	168 km / h	176 km / h	154 km / h
Cruising speed	136 km / h	144 km / h	134 km / h
Range	450 km		-
Engine	1 × 5-cylinder radial engine Armstrong Siddeley Genet Major I (105 PS)	1 × Genet Major IA (140 hp)

Preserved copies

K4235 at the Fantasy of Flight Museum in Polk City, Florida

• HM580 / G – ACUU in the Imperial War Museum Duxford
• Rota I K4232 / SE – AZB in the Royal Air Force Museum in London
• K4243 / G-AHMJ in the RAF Museum
• AP507 / G – ACWP in the Science Museum in London
• MM30030 of the Regia Aeronautica as I – CIER in the Museo nazionale della scienza e della tecnologia Leonardo da Vinci in Milan
• SE – AEA of the Swedish Air Force in the Stockholm Technical Museum
• SE – AFI of the Swedish Air Force, as PH – HHH in the Aviodrome in Lelystad
• LV – FBL in the Museo Nacional de Aeronáutica de Argentina in Buenos Aires
• VH – USR in the Powerhouse Museum in Sydney.
• K4235 at the Fantasy of Flight Museum in Polk City, Florida.
• Leo C-302 F – BDAD in the Musée de l'Air et de l'Espace in Paris.

See also

• List of gyroplanes

literature

• Arthur WJG Ord-Hume: Autogiro - Rotary Wings Before the Helicopter. Mushroom Model Pub., 2009, ISBN 978-83-89450-83-8 , p. 96 ff., P. 189, p. 290 f.
• Bruce H. Charnov: From Autogiro to Gyroplane. Praeger Publishers, 2003, ISBN 1-56720-503-8 , p. 123 ff.
• TR Hiett: Cierva's rotating wings. In: AIR Enthusiast July / August 2003, pp. 26–31
• AJ Jackson: Avro Aircraft since 1908. Putnam, 1965, 2nd edition 1990, ISBN 0-85177-834-8 , pp. 348-351

Web links

Commons : Cierva C.30  - Collection of images, videos and audio files

Individual evidence

1. ↑ Arthur WJG Ord-Hume, 2009, p. 290