Marc Ramsey wrote:
Janos Bauer wrote:

So far you seemed to be the most competent in the GFAC team,


It has nothing to do with competence. I agree with some of your
opinions, others do not.

I mean, you usually aware of the technical background (security, GPS
issues, etc-etc). On the other hand you often refuse certain suggestions
referring to existing rules and not to technical problems.

who else think different than you and what are the reasons

behind such an opinion?

Tradition is a big factor. The perceived (but not adequately studied,
in my opinion) inaccuracy of GPS altitude is another.

I also haven't really studied it but last Sunday it was the second
time when I had to fly xc without variometer and I was happy with the
simple GPS (no WAAS etc.) based palm&soaringpilot combo. I think it
would be impossible if there was really huge error (bigger than on those
20 year old barographs).

Can we involve him/her in this open discussion?
Maybe that member should visit an average club and see how these
barographs and barograms are treated...


It doesn't matter how they are treated, as long as they can be
successfully calibrated within the set interval. The corrected pressure
altitudes taken from a barogram may be off by a hundred feet or so, but
they still provide a more accurate measurement of the precise form of
altitude required by the current IGC rules, than any COTS GPS.

I don't think they are calibrated for all the temperatures. I don't
think all the mechanical impacts can be handled by calibration (I myself
(saw others do it few times) locked out the needle of one old smoky
barograph and we had to bent it back to working position, how do you
handle such an "impact"?) And the most important issue, what I stated
befo neither barographs nor cameras are sealed by OO on most of the
places I visited...
No one wants to cheat with them, it's just the way things going on
some (maybe most) places.

/Janos