Check your assumptions on GPS altitude. In my experience, it is very
similar to pressure altitude and doesn't suffer from the problems of
pressure altitude. I believe GPS altitude to be as good or better than
pressure altitude for all practical purposes.
STF I get very good STF info from my handheld. If it says to fly 80kts
around the last turnpoint and on home, I fly 80 and arrive home at pattern
altitude, just as programmed.

Brent
"BJen" wrote in message
...
glide around a TP before going home in wind. Presumably
this would have to be displayed as "altitude required"
unless it know current altitude somehow.

If the PDA knows altitude from an input, it can display
which fields you can reach, and whether you are high or low
on final glide. GPS altitude is relatively poor, but is one
option for getting current altitude info to the PDA. I
suppose you could input it manually, but that doesn't sound
practical. The best is a pressure sensor, but that would
mean getting altitude info from either a flight computer
(same as the airspeed problem above) or a Flight Recorder
that outputs its pressure altitude. Does the Volkslogger
give pressure alt to the PDA? Reading between the lines on
the PDA summaries I think it does.

For vario functions, it looks like it would need access to
TE. That's only available from a vario or flight computer.
I suppose it could fake it with altitude info for non-TE or
pseudo TE using wind and ground speed info. Do any do this?

For STF, it again needs TE from a vario or flight computer,
but I suppose it could fake it as above.

Does that sound right?