The project is the result of a decision by a group of friends at the Getafe Ultralight Club to commemorate the centenary of Juan de la Cierva’s historic first flight in his C.4 during January 1923. Following more than a thousand hours of design and fabrication work, the replica C.4 was ready for its official unveiling in January at Getafe Air Base, not far from the very spot where the original had first taken flight a hundred years earlier. The public unveiling took place at Camarenilla aerodrome March 2013, but the team chose to move the aircraft to Ocaña for its first flight. They disassembled the replica C.4 in the morning, driving it to the historic Ocaña Aerodrome by truck and then reassembling it.
Initial ground tests without the (unpowered) main rotor fitted, were carried out to check the engine operation and to test the aircraft in high-speed taxiing. After the crew fitted the rotor, a test run took place just a little after 6:00 p.m. local time. Pilot Fernando Roselló began the taxi run – but the autogiro lifted off briefly and then landed gently.
After this small jump, other takeoffs followed, until, finally, the Cierva took off and completed a couple of full circuits. Nerves, illusion and adrenaline were rewarded by seeing the autogyro take off from the ground without incident and land again successfully.
This particular early model does not having direct control through the inclination of the rotor hub, but rather still retains roll and elevator control with ailerons and rudder. While the replica C.4 stays true to much of the original design concept, the replica team chose to include some safety concessions, such as a modern engine and a well-proven, two-bladed rotor design (in place of the original four-bladed system which had only a marginal useful life of just a few hours flight time). One of the team engineers added that the rotor system, as it is without direct control, is based on Cierva’s patent, number 100595 of Dec 1926.
After alighting, Fernando Roselló stated that the aircraft behaved just as he had expected. It is a very stable aircraft, but since it lacks direct control (using aerodynamic control instead) it is slower to respond to control input. He flew as slowly as 50km/h and estimated a cruise of about 80km/h at about 4,500rpm, comparing it to 4,700rpm on his 80HP Rotax powered 912 gyroplane which flew at 80km/h with a positive variometer (rate of climb indicator).
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