Michael,

Good point. I'll add it to the list of "issues to be resolved". My gut is
that for Silver/Gold badge flights a barogram could be an acceptable means
of altitude verification in combination with camera (if distance is
involved), as long as that method of validation continues to be supported by
the IGC.

In terms of the cost being "nil", at some point the barograph has to be sent
to an approved facility for recalibration, no? Around here, that sets us
back around $40. So, there is a recurring cost, whereas the GPS cost is a
one-time event.

P3

"Michel Talon" wrote in message
...
Papa3 wrote:
Marc or others,

As I've dug deeper into this subject, the issue of geometric altitude
appears to be one of the true obstacles to the adoption of COTS units.
Is
there a public record anywhere of specifically what objections the
"members
of the IGC, or even GFAC" have raised? In doing just some basic
research
(along with the help of a major instrument manufacturer) it became
pretty
obvious that geometric altitude is the way to go at this stage.

Regards,

Erik Mann


"Marc Ramsey" wrote in message
. com...

My is opinion is (and has been for years) that the IGC should switch
over to using geometric altitude, which would allow use of GPS-derived
altitude with appropriate error bars. But, my opinion is not that of
the majority of members of the IGC, or even GFAC, at this point.

Marc


Suppose that one switches to "geometric altitude". What about people
who used to document their flights with barogaphs? Here all clubs have
barographs and lend them to the pilots when necessary. Hence the cost is
nil, which is certainly cheaper than the cheapest GPS.




--

Michel TALON