Most of the planes and all helicopters from Real Flight comes with a HUD like this:
This simple but helpful HUD shows you importend parameters from your plane or helicopter:
-Cam setting (Touch the HUD somewhere to changes the 5/6 Cam presets)
-Fuel indicator (Say 'refuel' in chat)
-Altitude above sea level or real altitide above ground display (Say 'alt' in chat)
-Speed in m/s
-Compass
-Artificial Horizon
-Throttle / Multidisplay
The HUD can have a different look (size from letters) on your screen. It depends on the settings from your computer screen. I use a 1440 * 900 pixel screen in my mac book pro and running Second Life in a window about 1200 pixels. If your screen resolution is smaler the HUD can look different.
Edit the position from the HUD: Rightklick choose 'Edit'. Now zoom out. Grab the arrow keys to move position from HUD.
VT221 Pegasus
CH-46 Sea Knight
LC440 Crane