Legal Notice: All DUC propellers have a maximum lifetime limited to 600h on direct drive engines (i.e Jabiru, UL Power, Continental, Volkswagen, Limbach) and 800h on Rotax and HKS engines. Structural guarantee is 6 months from date of payment. Average lead time is 2 months from date of payment.

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Contents of this page

1°) Swirl Carbon model

1.1) Specifications

1.2) Manufacturing characteristics

1.3) Operational characteristics

1.3.1) Static characteristics

1.3.2) Dynamic characteristics

1.4) Overall Results

2°) Swirl inconel model

3°) Swirl reinforced model

4°) The construction in details

4.1) High Tech construction

4.2) Minimisation of gyroscopic effects

4.3) Very low weight

4.4) Very small momentum

4.5) Modularity

4.6) use of high resistance and durable material

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SWIRL carbon model

For high-speed aircraft up to 135 Kts (250 Km/Hr)
Following the success of the windspoon propeller and after many years of research, development and extensive testing, DUC Propellers launched its new "SWIRL" model onto the market for ultra light and faster aircraft. Whereas the windspoon has been optimized to provide maximum thrust at slow airspeed and for pusher configuration, the Swirl has been optimized to provide high efficiency at higher cruise speed.
The propeller pitch is ground-adjustable and exhibits a constant speed effect by its aerodynamic design: at high speed, the power output is incomparably greater than the brands and models offered by other manufacturers who do not use this effect.
 

Specifications

• The diameter ranges from 1,440mm to 1,740 mm so that you are sure to get the exact model your aircraft requires.
• Weight of the 2 blade = 2.57 kg. (Full Set)
• Weight of the 3 blade = 3.38 kg. (Full Set)
• For Tractive or Pusher configuration
• Forged carbon hub: Resistance equivalent as forged aluminium alloys with half the weight. Read test results.
• The adjustment needs to be performed using the recommended tools in accordance with the assembly documentation.
• The initial adjustment for the Rotax 912 and 912S engines should be 20º.
• Up to date DUC propellers detailed instructions for mounting and adjustment downloadable here.
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Manufacturing Characteristics

• 100% Highest Quality Carbon Fibre: Enables the design of complex and high performance profile making this model the only one of its kind. This high quality propeller is as far as we know the only model that comes with a 6 year structural guarantee.

• Forge Carbon moulding process: Enables the design of complex shapes, perfect reproduction, smooth skin and thin trailing edge that result in more power and less fuel consumption and noise emission

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Operational Characteristics

Static Characteristics

• Ground pitch adjustable: Get the exact setting that provides the best performances for YOUR aircraft.Change the settings to adapt to new needs.
• Modular Structure: Get replacement blade and all spares you need. If the propeller goes onto another aircraft, adapt it to its new needs (3 blade->2 blade, Standard Spinner->Turbo Spinner, other diameter etc.)

Dynamic Characteristics

• Absence of reverse torque coupling: Increase propeller life time

• Absence of rotational momentum: Better safety and longer engine life time

• Minimal gyroscopic effect: Better flight-handling characteristics

• Reduced noise: Improve pilot comfort and safety by reducing the noise level inside your cabin, and reduce pilot exhaustion on long trips

• Constant Speed Effect: High-Tech aerodynamic profile that gives 90% of the benefits of a full CSU for a much lower cost and maintenance complexity

Overall  Results

1. Increased output power
2. Weight Reduction
3. Noise Reduction
4. Fuel consumption reduction
5. Longer life time

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SWIRL inconel model

Similar to the SWIRL carbon model but with a shielded leading edge.
The INCONEL SWIRL blade has a very hard Inconel stainless steel insert to protect the leading edge. This propeller is very suited to a hostile environment (sand, gravel, etc....).
This shielding provides better:

• Protection: increases the life time of the propeller.
• Rigidity: Maintains the performance when cruising at speeds greater than 135 Kts (250 km/Hr) and for engines over 100 hp. The upper limit of this model is 160 hp.

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SWIRL reinforced model

The SWIRL - R blades have a Reinforced Structure because they are intended to equip the very powerful engines (above 160 hp) like the VERNER twin-cylinder engine for better rigidity and to avoid a blade distortion due to the engine torque.
The reinforced model is available with a standard or inconel leading edge.
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The Construction in details

High-Tech construction

Design using CAD softwares and Carbon Process technology. Manufacturing using Layers of high-resistance carbon with a Rohacell core, polymerized with optimisation of the fibre interlacing. Use of high pressure press with high temperature oil circulating into the mould.

All this means that the blade retains its profile no matter what forces are applied to its profile, in such a way as to ensure optimal mechanical characteristics, that is:

 

                     - Thrust
                     - Efficiency
                     - Minimal torsion coupling
                     - Resistance to fatigue and other benefits.
 

Minimisation of Gyroscopic effect

The minimisation of the gyroscopic effect translates into excellent aircraft manoeuvrability characteristics and exceptional ease of flight handling.
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Very Low Weight

An example with a Tecnam Sierra RG Rotax 912S with a DUC SWIRL Inconel 1740mm that provides 90% of the benefits of a CSU propeller that would weight 9 Kg and therefore wouldn't comply with Rotax Inertia momentum specifications wich result in voiding Rotax's warranty.
The Swirl weighs 4,5 Kg for the full set of propeller and the additional Carbon Fiber Spinner and forge carbon Back Plate. The Sierra RG requires the longest and heaviest adaptator spacer 912H 80mm that weighs 1,5 Kg. That brings the total weight "ready to fly" to 6 Kg which is way below the competition.
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Very Small Momentum

As a consequence, wear forces on the axles, gears, bearings, silentblocs, etc. are also very minimal. This prolongs the life of the engine and increases flight safety.
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Modularity

Possibility to choose:

• The number of blades
• The rotation way
• The ground adjustment pitch of the propeller
• Standard or Inconel leading edge
• A Reinforced Structure

This allows the propeller to be adapted to the engine and gearing and tuning of the performance to the engine/gearbox combination.
Back to TOP This allow the manufacturing of a propeller of the highest quality available on the market. As far as we know the DUC FC and SWIRL are the only propellers that come with a 6 year Structural Guarantee.