A-10 (cup works these dont) if you go into first person and switch weapons (F) it should display different sights depending on ordinance (such as the bombs having a ring with a line to show you how far it will drop and its best guess as to where it will land) missiles create a ( ) sight to lock on with yet do not lock unless within 700m of the target and or the sight will not let you lock at all with any weapons.

the gau 8 sight should move and shift with the terrain and the planes angle to adjust for the drop and or other factors to help you aim and it stays static like the bomb sight which should move shift and slide around the hud in first person