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AFormX model R(e) racer

In 2018 AFormX had noticed that the Royal Aeronautical Society with Light Aircraft Association and Air Race E issued a joint design competition. The design challenge was to design an e-racer and to test-fly and race it in the the X-plane environment around a 5 km pylon track. Since we already at that time had a large experience base both with electric aircraft and with X-plane based simulations, we decided to participate in this design competition. From the outset we were participating in this design competition with a single goal: TO WIN.


To have a realistic chance of winning we had decided to follow three main design principles:

  • configure the aircraft so that it makes full use of distributed electric propulsion
  • to base the design in the currently feasible technology and take into account the available technology weights and dimensions
  • to leverage our hardware and knowledge in VR to provide the optimum pilot performance in the racing portion of the challenge
Main design choices
Overview of main design choices


This was a special simulator for us at that time, since it did not include any hardware. The work was done only on the model and the design assumptions on which the model was based.

The design was done through the summer of 2019 and included cooperation from our industry partners like Pipistrel, Emrax and Kanardia. For this project our team was enhanced by Alex Kraljič who did the stability derivatives. We had used the power of early simulation in X-plane to iterate the basic design configurations quickly and this was an important enabler for our conceptual design work.

Basic configuration test
Basic configuration test
Fuselage drag simulation in OpenFoam
Fuselage drag simulation in OpenFoam. On this basis the Cd was determined for the X-plane model

For the tuning of the design we fed the X-plane model data from different engineering softwares like OpenFoam.

Race time around the pylons
Race time around the pylons.

The second, but concurrent part of the project was the modelling of the externals and internals of the racer.

The end product submitted to the RAeS board was a technical report, the simulation and the recording of a lap flown in the X-plane environment. Therefore the last stage of the project was to fly the aircraft with the frozen configuration around the pylons and ensure that the pilot skill applied capitalizes on the inherent qualities of the design.

The design was submitted in September 2019 to competition field of more than 30 entries from a dozen countries. A winner of the RAeS competition was defined as any of the top three entries.


In November 2021 we had received the notification that we are a winner of the RAeS competition. This was a wonderful achievement for us and still remains one of the highlights of all AFormX projects.


To highlight the importance of this event not only for AFormX team, but also for the Slovene aircraft industry encompassed in our racer the Ambassador of Republic of Slovenia Mr. Tadej Rupel attended the Royal Aeronautical Society in London in december 2019.

Presenting the AFormX Model R(e) at RAES, London
Presenting the AFormX Model R(e) at RAES, London