OK I get the feeling nobody is going to guess what I have in mind.

Absolutely the cheapest way to do an EFIS is use voice synthesizing
technology.  No expensive LCD, LED or PDA at all.
Although bar graph LEDs are a very cheap way to go but they do take
up space on the instrument panel and suck power.

Everybody that flies an airplane has a head set.

"Your EGT on rotor one is 1400 degrees."
"Your EGT on rotor two is 1450 degrees."
"Your coolant temp is 220 degrees."
"Your oil pressure is 80 psi."
"etc., etc., etc.."

You could push one of several buttons each with different info on
the stick or on the instrument panel to get the info when you
wanted it or allow the system to inform you when something went
out of preset limits. If something started changing too
fast it could warn you automatically.

It could also work as a stall warning.

"PUSH THE STICK YOU ARE GOING TO STALL!"
"PUSH THE STICK YOU ARE GOING TO STALL!"
"PUSH THE STICK YOU ARE GOING TO STALL!"

The possibilities are infinite. The cost and panel space are minimal.

http://www.rcsys.com

Paul Lamar

Paul, this is not a bad idea per se, but here are some considerations:
1) Some people assimilate data better by visio than by audio. I'm one of them.

2) You can look at properly positioned multiple analog gauges in the blink of
an eye (literally) and see if one is in an abnormal position, whereas it would
take longer to read digital numbers and several seconds to get the same info
by audio.

However, that last point is overcome with a simple light (LED) that comes on
(or a voice alert) if any value exceeds programmed parameters, and one can
then look closer at the digital readouts to see what's up. I like to have all
values visible simultaneously, with no buttons to push, whereas others can
live with or prefer the warning light and pushing buttons (like the Grand
Rapids Tech EIS - probably the cheapest at $473 including probes!). I would
have a hard time competing with the Grand Rapids EIS, unless someone insisted
on having all parameters visible simultaneously. I could probably not market
my simple system for less than $200 - $300 plus probes.

So, your system would work for some, if it's only used as an alerting system,
but would hardly work if used for tuning the engine (e.g. mixture, spark
advance, etc.).

Finn

It depends on the mode. The EGT could be repeated rapidly
for tuning purposes.

"1430"
"1435"
"1442"
"1446"

The thing about this system is it is almost infinitely expandable at little 
or no cost while a display system must switch screens. Also a large
display with many pixels is very costly and takes up a lot of panel
space. This takes little or no panel space.

Also this is not meant to sell in the same price ranges as an LCD
display. You buy what you can afford. This is really designed for
the lower end on the EFIS price scale.

Paul Lamar
 
The AirCraft Rotary Engine NewsLetter.              Powered by Linux.
ACRE NL web site.
http://home.earthlink.net/~rotaryeng/            http://www.linux.org