 | This article includes a list ofgeneral references, butit lacks sufficient correspondinginline citations. Please help toimprove this article byintroducing more precise citations.(May 2017) (Learn how and when to remove this message) |
| C.30 | |
|---|---|
 Cierva C.30 climbing out on take off | |
| General information | |
| Type | Autogyro |
| Designer | Juan de la Cierva |
| Number built | 148 |
| History | |
| Introduction date | 1934 |
| First flight | April 1933 |
| Variant | Cierva C.40 |
TheCierva C.30 is anautogyro designed byJuan de la Cierva and built under licence from theCierva Autogiro Company byA V Roe & Co Ltd (Avro) as theAvro 671,Lioré-et-Olivier as theLeO C.301, andFocke-Wulf.
Before the experimentalCierva C.19 Mk V, autogyros had been controlled in the same way as fixed-wing aircraft, that is by deflecting the air flowing over moving surfaces such as ailerons, elevators and rudder. At the very low speeds encountered in autogyro flight, particularly during landing, these controls became ineffective. The experimental machine showed that the way forward was a tilting rotor hub fitted with a hanging stick extending to the pilot's cockpit with which he could change the rotor plane. This was known as direct control and was fitted to theC.30.[1] The production variant, called C.30A in England, was preceded by several development machines.
The first production design in the series was the C.30, a radial-engined autogyro with a three-blade, 37 ft (11.3 m) rotor mounted on an aft-leaning tripod, the control column extending into the rear of the two cockpits. The engine was the five-cylinder, 105 hp (78 kW)Armstrong Siddeley Genet Major I used in the C.19 series. The fabric-covered fuselage carried an unbraced tailplane, without elevators but with turned-up tips. The port side of the tailplane had an inverted aerofoil section to counter roll-axis torque produced by the propeller. As with most autogyros, a high vertical tail was precluded by the sagging resting rotor, so the dorsal fin was long and low, extending well aft of the tailplane like a fixed rudder and augmented by a ventral fin. The wide-track undercarriage had a pair of single, wire-braced legs and a small tail wheel was fitted. This model flew in April 1933. It was followed by four improved machines designated C.30P (P here for pre-production) which differed in having a four-legged pyramid rotor mounting and a reinforced undercarriage with three struts per side. The rotor could be folded rearwards for transport. The C.30P used the more powerful (140 hp, 104 kW) seven-cylinderArmstrong Siddeley Genet Major IA radial engine.
The production model, called the C.30A byAvro, was built under licence in Britain, France and Germany and was similar to the C.30P. The main alteration was a further increase in undercarriage track with revised strutting, the uppermost leg having a pronounced knee with wire bracing. There was additional bracing to thetailplane and both it and the fin carried small movable trimming surfaces. Each licensee used nationally built engines and used slightly different names. In all, 143 production C.30s were built, making it by far the most numerous pre-war autogyro.
Between 1933 and 1936, de la Cierva used one C.30A (G-ACWF) to test his last contribution to autogyro development before his death in the crash of aKLMDouglas DC-2 airliner when taking off atCroydon Airfield in England on 9 December 1936. To enable the autogyro to take off without forward ground travel, Cierva produced the "autodynamic" rotor head, which allowed the rotor to be spun up by the engine in the usual way but to higher than take-off r.p.m at zero rotor incidence and then to reach operational positive pitch suddenly enough to jump some 20 ft (6 m) upwards.
At least oneRoyal Air Force (RAF) C.30A was onfloats as aSea Rota in January 1935.[2]
Avro obtained the licence in 1934 and subsequently built 78 examples, under their model designation, fitted with anArmstrong Siddeley Genet Major IA (known in the RAF as the Civet 1) 7-cylinder radial engine producing 140 hp (100 kW). The first production C.30A was delivered in July 1934.
Twenty-five aircraft were built in France byLioré-et-Olivier as the LeO C.301 with a 175 hp (130 kW)Salmson 9NE 9-cylinder radial engine.
Forty aircraft were built in Germany as the Focke-Wulf Fw 30 Heuschrecke (Grasshopper) with a 140 hp (105 kW)Siemens Sh 14A 7-cylinder radial engine.[3][4]
_(14714156820).jpg)
Of the 66 non-RAF aircraft built in the UK by Avro, 37 appeared at least for a while on the UK register.[5] Some (maybe a dozen) were sold abroad, but others were flown by wealthy enthusiasts and by flying clubs who offered autogyro training. By the end of the decade, private flyers were moving back to the comforts and economies of fixed-wing aircraft and more C.30s moved abroad leaving the Autogyro Flying Club atLondon Air Park, Hanworth as the major UK user. 26 aircraft were directly exported by Avro. These went both to private owners and to foreign air forces who wish to investigate the autogyro's potential.
In 1934, one Spanish Navy C.30 piloted by Cierva landed on the SpanishSeaplane tenderDedalo anchored inValencia harbour and later made a takeoff.[6]
In September 1935, five members of the Lithuanian Aero Club flew C.30A in the "air train" together with the gliderSchneider Grunau Baby and the airplanede Havilland DH.60 Moth over theBaltic Sea states:Kaunas,Riga,Tallinn,Helsinki.[7]
Twelve C.30As built by Avro for the Royal Air Force (RAF) entered service as theAvro 671 Rota Mk 1 (SerialsK4230 toK4239 andK4296 &K4775). The twelve were delivered between 1934 and 1935. They equipped theSchool of Army Co-operation atRAF Old Sarum near Salisbury.
Many of the surviving civil aircraft were also taken into RAF service between 1939 and 1940. In 1940, they equipped1448 Flt. atRAF Duxford. Later they equipped529 Sqn. atRAF Halton onradar calibration work: disbanded in October 1945, the twelve survivors were sold on to civilian owners.
Most of these did not last long, although two were used for pilot rotary wing experience byFairey in theirFairey Gyrodyne helicopter programme.Rota Towels kept one ex-RAF Rota airworthyG-AHTZ until an accident in 1958.G-ACUU, the Imperial War Museum's C.30A exhibit atDuxford had one of the longest active lives. It joinedAir Service Training Ltd in 1934, was impressed (as RotaHM580) in 1942, serving with 529 Squadron and returning to civil use by G.S. Baker based at Birmingham'sElmdon Airport with its original registration plus the nicknameBilly Boy and was not withdrawn from use until 1960.
After several years of work at the Maestranza Aérea de Albacete, on 15 January 1998, a C.30 was flown again. It was piloted by Lieutenant Colonel Fernando Iglesia. After an accident in June 2000, which almost left the pilot without an arm, the aircraft was handed over to theMuseum of Aeronautics and Astronautics, located at theCuatro Vientos air base (Madrid).[8][9]
General characteristics
Performance
