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°) DUC FC Windspoon Model

1.1) Specifications

1.2) Manufacturing Characteristics

1.3) Operational Characteristics

1.3.1) Static Characteristics

1.3.2) Dynamic Characteristics

1.3.3) Overall Results

2°) Exclusive DUC FC Design

3°) The DUC FC in details

3.1) Double Twist Clark YH extra flat profile

3.2) High-Tech construction

3.3) Minimisation of Gyroscopic effects

3.4) Very low weight

3.5) Very small momentum

3.6) Modularity

3.7) use of high resistance and durable materials

4°) Reinforced DUC FC Model

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DUC FC Windspoon Model

The design of the windspoon propeller is optimized for speed up to 80 Kts 150Km/h).
The long cord and complex profile associated with specific blade tips will produce a high level of thrust at low air speed:

• In pusher configuration, the windspoon will use airflow on the periphery of the propeller to produce more thrust than any other propeller. This specific tip shape is possible only thanks to the use of a high density dynamic Rohacell foam core associated with high quality lawyers of carbon fibre placed at 0° to carry centrifugal forces and 32° to carry propulsive forces.

• On a puller configuration, the Windspoon will produce more thrust at low airspeed than any other propeller thanks to the long cord and a contrary twist to control the air flow over the whole surface of the blades and an axis of forward twist for improvement of the load-carrying capacity.

As an example, a glider tower Dynamic WT9 (Aerospool) Rotax 912ULS with a windspoon propeller will achieve better climb rate while towing than a DR400 Lycoming 180hp.



The propeller pitch is ground-adjustable and exhibits a complex shape called WINDSPOON allowing a reduction of the vortex created at the tip of blade, a contrary twist to control the air flow over the whole of the Windspoon surface, an axis of forward twist for an improvement of the load-carrying capacity and a higher effectiveness.

Specifications

• Diameter = 1,730 mm.
• 2 blade weight = 2.38 kg. (Full Set)
• 3 blade weight = 3.12 kg. (Full Set)
• For Tractive or Pusher configuration
• Forged carbon hub: Resistance equivalent as forged aluminium alloys with half the weight. Read the test results.
• The adjustment needs to be performed using the recommended tools in accordance with the assembly documentation.
• Adjustment of the propeller pitch must be made using the recommended adjustment tool which is applied on the leading edge of the propeller 14cm from the tip.
• The initial adjustment of the pitch angle depends upon the type of engine.
• 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

• Windspoon Effect: High-Tech aerodynamic profile that gives a considerable increase in thrust especially for Pusher configuration.

Overall  Results

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

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Exclusive DUC FC design

The Windspoon

Improves considerably the thrust especially on Pusher configuration

The Flat Profile

With an enormous resistance to twisting, especially at the tip, which comes exclusively from the use of carbon fibre.

 

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The Duc FC in details

Double Twist CLARK YH extra flat profile

Significant twist reduces torsion at the blade tip and brings the centre of gravity to the centre of the axis of rotation in such a way as to reduce the torsion momentum the base of the blade.

This phenomenon is further enhanced by the trapezoidal shape which extends to the blade tip.

 

 

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, a DUC FC weighs 530 grams per blade and 1610 grams for the assembly components. This yields a total of 3200 grams for a complete 3 blade propeller.
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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
   - 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.

 

Use of high-resistance and durable materials

This ensures excellent protection of the blade tips and excellent propeller performance.

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.

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Reinforced DUC FC model

The  DUC FC-R blades have a Reinforced Structure because they are intended to equip with the very powerful engines like the Rotax 914 (i.e ELA-08) or Rotax 912 RTS (i.e Xenon 2) for better rigidity and to avoid a blade distortion due to the engine torque.