Flat Earth - The Horizon is NOT always at eye level.

One argument the Flat Earther’s use is that the Horizon appears to rise as you gain altitude. They never provide an accurate method of measuring the Horizon against true level. In this video the HUD show an accurate level position in steadly level flight. (the two small circles). At 47,000ft you can see clearly the Horizon has dropped below this level and this is more proof the Earth is Curved.