– FS2004 Blue Sky Environment Upgrade flight2000it 18 years ago FS2004 Blue Sky Environment Upgrade. Includes dawn, morning, day, noon and dusk sky textures, designed for detail and performance. By Alex Ranc. 500 Kb FS2004 – The Natural World 2019FS2004 – The Natural World 2019FS2004 – HDE – High Definition Environment v2