google : up side down Sturmovik , prvni odkaz :

ISSUE: Game display is upside-down.
On some Intel and NVIDIA graphics cards that support display rotation, this game may be displayed upside-down.

SOLUTION: Disable the rotation feature in your display settings, or, alternatively, some card manufacturers allow a hot-key combination to be configured to rotate the display.
CTRL+ALT+UP or CTRL+ALT+DOWN are common default hotkeys. Please check your video card manufacturer's support site for more information