Atmospheric pressure, temp difference from the ICAO std atmosphere(ISA)
(4 feet per degree of ISA deviation times the number of thousands of
feet, if I recall correctly - bigger than the pressure differences),
and logger pressure sensor errors all play. My Volkslogger, on the
last 3 calibrations, reads several hundred feet higher than the
calibrated sensor at 18k. Logger pressure sensors are not accurate,
but are repeatably precise... the reason you do the altitude correction
on altitude gain badge applications in most cases. I imagine that a
sensor which was accurate would cost a lot more, which is not something
most folks want with loggers!

So, in my case, if I fly close to 17,999', it can appear I'm in class
A. My OLC claims, however, offer to send a copy of the baro cal
certificate to whoever wants it, to show I was legal on the flight...
Jumping to the conclusion that there is an infraction without the facts
is dangerous. I'm sure that few would post a similar flight without a
reason like mine.

GPS altitude is above the GPS ellipsoid; it is also subject to bigger
errors than the horizontal errors (due to system design). Comparing
pressure and GPS altitude is problematic.

Dan

hans wrote:
In the past there was a function in the OLC that marked every flight
with a possible airspace infringement. The result of the airspace check
was made available to the pilot before the flight was claimable for the
OLC. But the peer pressure was too strong for some of the buddies of Mr.
Rose and so first this feature and later the person that had implemented
this feature were removed from the OLC.


flying_monkey schrieb:
SAM 303a wrote:
What is your point? That we need another set of watchdogs?
We shouldn't condone or copy the behaviour you've identified, but I don't
see how it benefits the sport to point it out to the authorities or make a
stink on RAS.
I bet with a little Googling you could find contact info for The Offender.
If you feel so strongly why don't you contact The Offender?

Geez! I'm not trying to point this out to the authorities, or make any
kind of stink. Oh, yeah, I know that the FAA folks probably read this,
but I bet they'd be a lot more impressed if we started policing this
widely ourselves as a group. We all need to police ourselves so that
we don't break the rules, and on the remote chance that we do, we don't
advertise it to the world. A little peer pressure would work wonders
here. Contacting the offender directly wouldn't do this. It might
correct this one instance, and get that one flight claim retracted, but
if the word is spread wider, maybe people will think before they
infringe or post.

Ed