This model is really huge. The scale is approximately 1/4, the rotor diameter is 2.80 meters! The weight of the thing is around 24 kilograms. Here is the video:
It is equipped with a gas-turbine engine – the same type of engine as the real Mi-8 helicopter has.
Also there is a video of a huge Mi-24 HIND “Flying tank” helicopter:
Also with a real turbine engine.