Rotorcraft in the Thirties

Juan Cierva's gyroplane designs are where it's at in the Thirties -- actual helicopters are pretty pathetic creatures at this time.

Kamov A-7

• Single rotor autogyro, carried pilot + gunner/observer/radio operator. 480 HP radial engine, top speed 130 mph, climb rate 1,000 feet per minute, ceiling 15,000 feet, range 300 miles. Wingspan 34', empty weight 3400 lbs, takeoff weight 5100 lbs. Developed in 1934 as an improvement on the Cierva copies previously in service, but very few were built (perhaps as few as seven) and first shown at at military parade on 18 August 1935. Has all-metal skin, radio, rotor-starting clutch for vertical takeoff capability, folding wings and rotor for transport; armament is two fixed forward-firing rifle-caliber machineguns (PV-1, the aircooled version of the Maxim), and one flexible gun, plus four bomb pylons for 100 kg bombs! In addition from 1937, the craft can carry six RS-82 rockets:  four firing forwards, and two to the rear!

• The Kamov design bureau was also involved in the design of a flyinig tank, by adding an autogyro rotor and a pusher propellor to a T-37A tank.

   

Breguet-Dorand Gyroplane

• Experimental two (coaxial) rotor helicopter; Hispano-Wright engine of 420 HP; pilot + 1 passenger. 67 MPH top speed, ceiling 600', range 60 miles, rotor diameter 54', 4500 lbs takeoff weight. This French helicopter sets many world records in 1935.

Cierva C-19 or C-30 Autogiro

• Single rotor autogyro, various engines 140 HP to 300 HP, pilot + 1 or 2 passengers, rotor diameter 42', top speed 105-123 mph (depending on manufacturer and engine), climb rate 1,000 feet per minute, ceiling up to 18,000 feet, range 275 to 300 miles, takeoff weight 1800 lbs. Experimental models have rotor-starting clutch for vertical takeoff capability. Cost (est.) $8,000. Cierva's first autogyro flew in 1923; he exhibited his craft in America in August, 1929 at the Cleveland Air Races; currently produced in America by Pitcairn (PCA-2 is current in 1933, with a 300 HP Wright R-975 radial engine), Kellett; in Germany by Focke-Wulf and Focke-Achgelis; in France by the Loire Company; and in Russia by TsAGI. One of the Pitcairn types served in Nicaragua with the US Marines. Also available with floats.

Curtiss-Bleeker

• Experimental single-rotor helicopter; Pratt & Whitney 420 HP "Wasp" engine, pilot + 1 passenger, top speed 20 mph, gross weight 3300 lbs. Built 1930 in the U.S., this craft had a centrally-mounted engine rotating with the four rotors, and powering four propellors, one mounted mid-span on each rotor; properly described as "magnificently complex", see picture.

Flettner Fl-265 Kolibri

• Experimental two-rotor (intermeshing) helicopter; powered by 140 HP Siemens-Halske engine; pilot + 2 passengers; 40' rotor diameter, takeoff weight 2200 lbs, top speed 100 mph. Seven were built for the German Navy in 1939; most of his pre-1937 designs resembled Cierva autogyros.

Focke-Achgelis Fa-61

• Experimental two-rotor helicopter, powered by Bramo 160 HP engine. Pilot only, top speed 77 mph, ceiling 7800', 2100 lbs takeoff weight. This German helicopter first flew in 1937.

Gyelikogyr I-4

• Experimental single-rotor compound helicopter; powered by four de Havilland Gipsy III engines of 120 HP each (tip-mounted) pulling the 77' diameter four-bladed rotor, and a Wright Whirlwind J-6 engine of 300 HP driving the propellor. Pilot + 5 passengers, takeoff wieght 6600 lbs. Built in 1932 in the Soviet Union, designed by the Italian Vittorio Isacco, but had many mechanical difficulties (not the least of which were the very-Britishly-complicated de Havilland engines).

Yuriev 3-EA

• Experimental single-rotor helicopter; "noteworthy" performance of 13 mph top speed, 15 minutes flying time, 2000' ceiling. Constructed by Soviet Russia's TsAGI in 1933, typical of actual flying helicopters of the early Thirties.

Wilford Gyroplane

• Experimental single-rotor autogyro; powered by 165 HP Jacobs engine, rotor diameter 30', 1 pilot, takeoff weight 1800 lbs, max 115 mph, min 30 mph. One of the more controllable craft of the time.