Sky Power GmbH has strengthened its partnership with Czech Republic-based Mejzlik Propeller.

This has come after the growing number of enquiries concerning complete drive units for unmanned aerial systems (UAS). The objective is the development of propellers coordinated individually to the engine and the customer application.

Sky Power GmbH managing partner Karl Schudt said: “In past projects, we were approached again and again by our customers for propeller recommendations. Since we develop complete drive units for our customers that are coordinated to the customer application, the requests on the part of the customers were understandable.

“Since we didn’t want to set up our own propeller development department, we looked around for a partner who had the same understanding of quality as us.”

Schudt added: “We had already worked well together in the past and were convinced of the quality of carbon-fibre propellers.”

In the world of unmanned aviation, Mejzlik Propeller is well-known for its work. All propellers are manufactured from carbon fibre and can be adapted to a variety of features, forms and designs of the customer application and the outputs to be achieved.

Besides the size and the pitch, the number of blades, the weight, the carbon fibre material as well as the surface can also be adapted.

Mejzlik Propeller business development manager Jan Hruška said: “The propeller must perfectly match the engine, as only this way can an efficient utilisation of the entire drive unit be ensured.”

Furthermore, at Mejzlik Propeller particular attention is paid to the quality.

Jan Hruška added: “Our customers sometimes move sums running into millions in the air, if one counts the UAS and the payload together. Apart from this, in future flying over groups of people will become routine. Flying must, therefore, be absolutely safe. For this reason, the quality of the propeller must be given special attention in order to ensure safe flying.”

That’s why various propeller tests are carried out before delivery. Besides balance tests, an inner structure tests, optional RPM tests and visual quality inspection are performed.

Apart from that, for Sky Power there was a further incentive for the cooperation. Since every engine is coordinated to the customer specifications, so-called propeller curves are required.

Schudt said: “Very few propeller manufacturers can provide these, as the tests are complex. Based on these details and the computation models, we can calculate and develop the right propeller for every application”.

The velocity, the flight altitude, the rotational speed as well as the environmental conditions influence the performance of a propeller and consequently also that of the entire propulsion unit.

Hruška added: “To design an appropriate propeller, we also consider the data that we already have from the propellers previously designed and measured. Based on these measurements and our experience, we can adapt the design to your requirements and give you a basic idea, how the respective propeller behaves.”

Schudt went on to say: “This experience is important for us in order to provide our customers with a perfectly coordinated drive unit. Because this is what our customers expect.”

Both companies will, in future, work more closely together on customer projects. Schudt said: “In individual projects, we will fall back on the experience of our Czech colleagues very early on, if our customers also want to adopt this approach.”

In this case, the customer can expect a complete solution from a single source.