If you mean momentum as you you want the drone to continue moving after the input/key is released , but slowly come to a stop, you need to investigate interpolation functions that you can feed with delta seconds. Usually people use linear interpolation (look up lerp nodes), but in your case you will probably don’t want linear interpolation, but a curve interpolation function. This would make it so that if the period over which you want it to come to a stop is, say, 5 seconds, it moves further in the first second than in the second second, and so on.