The Rotax overload clutch comes as standard with all 912s engines. The overload clutch does not slip unless you approach the maximum torque capability of the crank shaft, it’s mainly there to protect the crank and the case incase of a prop strike.
The damping system in the gearbox also allows you to use very light propellers, most new lightweight sport aircraft use a lightweight composite propeller (foam core with a carbon fibre shell), 3 blade propellers can weigh less than 10lb enhancing overall performance.
The reason these aircraft are able to use such propellers is due to the overload clutch and the torsional vibration dampener that’s built into the gearbox. The same proper would not able to be safe to use on a direct drive engine due to the torsional vibration a direct drive would transfer to the propeller. This is the reason for having a heavyweight metal propeller on older direct drive engines.
For more information see:
US Distributor for ROTAX Aircraft Engines - [ Ссылка ]
UK Distributor for ROTAX Aircraft Engines - [ Ссылка ]
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