Without a method of converting the power produced by the engine into useful thrust an aircraft would just be sitting still and creating a lot of noise and not get anywhere. In the past, all kinds of different propeller designs were tried: sometimes flat wooden blades, from one bladed counter weighted to multiple blade models rotating at various speeds.
Most aircraft propellers are nowadays build from a fine selection of materials like wood, metals and carbon or other fibers to form a strong construction.
Founded in 1997, the DUC Hélices company specializes in the design and manufacture of carbon composite aircraft propellers. These are known, due to their aerodynamic blade design, to have a 'constant speed' effect.
The company has a complete range of propellers developed to equip all types of tractive and propulsive driven aircraft (CNSK / CNRA certified aircraft, 3-axis ultralight, pendulum, gyrocopter, paramotor, glider tug, UAV / UAV, etc.) from 40 up to 210 hp. The knowhow in aerodynamics and composite materials makes it possible to offer powerful, silent and robust propellers.
Since 2016, DUC propellers have been certified by EASA for 100 to 160 hp aircraft and even a 180 hp tug. They are also ISO 9001 certified, DUC Hélices controls their production system while guaranteeing a perfect after-sales service. Propeller blades are made within a mold in a high pressure/ temperature forge of which they own the patent rights. This results in a very robust and smooth surface of the blade. The hub is also made of carbon fiber.
The 'constant speed' effect is an aerodynamic effect due to the design of the propeller blades. The result of this effect is to achieve similar performance of a variable pitch propeller (short takeoff, rate of climb and high speed) but with a fixed pitch propeller. This effect is not based on the deformation of the blades, but only by the aerodynamic shape of the blades and the flexing under different loads and RPMs.
The outcome is that the engine RPM will stay more or less constant while the aircraft accelerates from climb speed to cruise speed. This effect has been confirmed by Viking Aircraft Engines with their company aircraft running a V130 engine.
DUC propellers meet all ULM & LSA regulations (EASA CS-LSA & ASTM 2506). However, they do not yet have the airplane certifications (EASA CS-VLA & CS-22). This process is currently in progress. Be sure to check with DUC on this.
The choice for a two or three bladed propeller is mainly dependant on the power output of the engine, RPM, noise levels, ground clearance and some other variables. DUC will advise you with the best choice as they have lots of experience with their propellers on a multitude of aircraft.
DUC Hélices has a complete product line of propellers suitable for a number of popular engines; spinners (cone) and spacers are also available for the following engine manufacturers: Rotax, Jabiru and the well known standard SAE-1 and SAE-2 mounting flanges.
Most propellers are available in right or left rotation, tractor or pusher configuration and some are even EASA certified. For more details on these Swirl or Flash propellers, see the website of DUC.
For the 2-axis trike ultralights (called ULM in France/Belgium) DUC is manufacturing the Spoon. This propeller has a distinctive spoon form at the end of the blade, its sort of bended. It reduces noise for pusher installations where the propeller gets much more turbulent air than with the tractor type aircraft (with the propeller on the nose).
The production facilities of DUC design, manufacturing and marketing activities are located in France, in the town of Lentilly near Lyon.
DUC Hélices/ Propellers can be contacted at the following addresses:
|DUC Hélices/ Propellers|
|Aérodrome de Villefranche-Tarare (LFHV)|
289 Avenue Odette & Edouard
|Durand, 69620 Frontenas, FRANCE|
|+32 474 721 269|
Text and images used with permission (pending) of DUC Propellers.Written by EAI.