Knight Paladin
You are wrong wrong wrong and misleading many aviators.
Once you leave the earth the ONLY relativity your aircraft has with the earth is gravity. The aircraft performs relative to the air supporting it and to gravitation attraction. Groundspeed becomes entirely irrelevant to manoeuvering and the earth only becomes significant in the vertical plane to earth.
Your momentum becomes relative to the air molecules or to whatever you run into be it another aircraft or a rock filled cloud.