We have found a very major bug in the physics engine.
If you hit around 230km/h in a certain direction. It's will give you a supersonic speed.
It only happens if you face a specific direction.
In Expansion, most of our helicopters go over this km/h, so the bug happens every time.
This is a link to the video, to show the bug: https://streamable.com/g5qmv5