Introduction to Rotax engine

Introduction to Rotax engine

Quick recap

Last update to One Man Helicopter v.04 brought a few changes mostly to Po1 personal helicopter, but also to whether manager to keep track on temperature changes at troposphere. This will relatively makes impact on engine performance depend of aircraft altitude as part of the introduction air properties in OMH. Next step in this field could be insertion of oxygen and density level versus engine/aircraft performance. Also logic responsible for counting and applying damage has been rewritten to get more distinguished differences between the damage types which is cover with sound and visual effects. See “Updates & Changes” on product page for more details.

Upcoming changes

Personal flying device P01 need to be rebuild in order to let this unit become more racing machine with sport ambition. Considering the fact that I want to add some more realism to this project, therefore I can not build it up on a motorbike engine. This was great for early prototyping, but now let’s move on.

Yahman Engine for One Man Helicopter


For this task we need to consider to use new engine type, and how it will impact the project. Up to now we based on Yahman engine from my imagination. Simple build with characteristic shape of motorbike engines, no expensive geometry. But also less autentic to have helicopter with engine from huge scooter. Well, Yahman is pretending to be a big 2l engine with V cylinders style but for P01 I want to something more designed for this segment. My suggestion at the moment is…


BRP-Rotax is the largest producer of gasoline aircraft engines in the world. During the last 40 years BRP-Rotax has invested in continuous design and development of Rotax aircraft engines. With low-operating costs, leading class power to weight ratio, well known reliability, it is no surprise that Rotax aircraft engines are the first choice of more than 220 aircraft manufacturers worldwide. The compact and lightweight design of Rotax aircraft engines has been developed by pilots for pilots for use on many kind of aircraft. For more see Flyrotax


Choice impact

There are several engine manufacturers on the market for small flying devices. Of course, for us the price does not matter so even Rolls Royce engines were taken into account. However, it is important to have access to reference materials and technical data to build model from it. Thanks to price and quality, Rotax found a lot of interest in this range. This has resulted in more and more people sharing their remakes and observations. And this is a great opportunity for me to understand better how these things work and use it in our project. To start with I chose the Rotax engine model 912 UL / A / F due to the fact that it has also rich upgrade options. This model at the start gives us 80 hp and we can raise it up to 141 hp depending on the components used, such as: fuel system, exhaust system, spark system, turbo and others. This could give us a chance to tune our machine based on the systems we have installed and this will create automatically more variants.


  • Much more realistic, 
  • People love engines,
  • Ease access to the reference materials collected on the Internet,
  • Access to real technical data on which we can support, such as: weight, rpm, fuel consumption, operational altitude, temperature, etc. 


  • To build a four-cylinder engine with all systems, cables, etc., equeles a much more expensive geometry in terms of polycount. 
  • Frame, transmission shaft, and rotors has to be redesign in order to fit this new engine type. 


It looks like we want to try it anyway, so in this and in the next weeks time going to be devoted for modeling entry model Rotax engine 912 with 80 hp and all extra systems to be able to upgrade this to 141 hp. As you can see many changes has to be done before we get this to work. All those changes are planned for P01 machine. In the future, if using Rotax engines makes us happier then for R01 and R05 we will prepare two stroke Rotax 582 UL engine with 65 hp with appropriate changes base on P01 template.


I am becoming more and more convinced that the nearest future belongs to electric motors and that is what I really want to do. The R and P series will be supported by internal combustion engines, but the next prototypes will be based on electric motors. Of course it would not be okay to jump over turboshaft engines without a word. So the solution in the future can be to extend the upgrade offer range from Rotax to turboshaft engines like Rolls-Royce RR300 with up to 240-300 shp power range at 91 kg. Wrrrum..

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