There is no stop a 180 on Red Eagle. The azimuth wheels are continuous through multiple revolutions. Only the L/R keys have that restriction. Steering with the mouse is the easiest, and most sensible, in most circumstances.
Marty
With precision steering off, the left or right arrow key will rapidly set you to 180. If you hold the Shift key while you do that, and first release the arrow key, you will then be able to steer through 180 with the mouse.