"tango4" wrote in message ...
The major problem with current HUD systems is that they are projected onto a
screen screwed to the instrument panel turtledeck. Fine if you are a fighter
jock and want to keep your eye on the bandit in front of you. Also good for
IFR types who actually don't need to look out the window anyway.

What is really needed in sailplanes are head mounted displays that keep an
image hovering in front of the pilot wherever his head is. A sailplane pilot
only looking out ahead is almost as bad as one focussed on a PDA strapped to
his leg.


Ian

Your description of current HUDs is somewhat misleading. HUD work by
projecting images, collimated to infinity, on a clear "combining
glass" on top of the instrument panel, in the pilots normal line of
sight. The projected symbology - attitude, heading, airspeed,
altitude, etc. is superimposed on the real world with a direct
correlation - in other words a 5 degree pitch up using the HUD scale
is a true 5 degree pitch, not a shrunk symbolic display as on a small
attitude indicator. Newer HUDs also allow projecting FLIR or LLTV
images - also collimated at infinity - on the HUD, so you have a
"virtual reality" display; cool at night. The importance of the
infinity collimation of the display is that you do not have to refocus
your eyes when looking at a HUD, you see the symbology when focused at
long distance. That is absolutely not true when "coming inside" to
read old fashioned steam gauges!

The downside is all the optics are HEAVY and power hungry, so don't
count on seeing them in a glider soon.

The newer fighters have Helmet-mounted displays that project all the
HUD symbology on their helmet visor. Still heavy, big, and power
hungry.

What I think we need for gliding is a nice big color navigation
display to replace the sectional chart that is becoming more and more
difficult to fold in our small cockpits - something that I can pull
out, look at, then put away to continue flying. Let's face it, after
awhile you can fly any glider by feel and audio vario, anyway.


Kirk