OLC max altitude self censorship

On Tuesday, February 12, 2019 at 10:19:50 PM UTC-6, wrote:
So my question is:Â* Has anyone using GPS-only recorders done the same -- effectively altitude "censored" yourself because of that very visible OLC altitude profile.Â* When I look at people's flights, I see lots of traces which "bounce" against that 5486m ceiling, at least over the western U.S. in the summer.Â* Sometimes, I see higher climbs with the pilot's comment that says something like, "Got ATC clearance into Class A".Â* Sometimes, I see excursions above 5486m with no comment.Â*


A related question to those who use fully IGC approved flight recorders with barometric sensors:Â* Do your .igc altitude numbers record your barometric or GPS altitudes?

Yes, I have experienced the same phenomenon over mountainous terrain. My primary flight logger is an Oudie2, which is connected to a portable FLARM. The GPS altitudes are typically at least 1,000 feet higher than my altimeter, whenever I climb above about 15,000' or so. The Oudie starts bleating an airspace warning before I even reach 17,000'. This is a nuisance on great soaring days in the mountains. On those days, I sometimes stay below 17,000' just to avoid the nuisance.

I had my altimeter checked and calibrated about a year ago, so I am very confident in its accuracy, as opposed to the GPS altitude. However, without a transponder, is there any record anywhere to prove that I have NOT busted airspace floors or ceilings? If I post an OLC claim with my Oudie, where is my proof that the Oudie altitude trace is wrong? Who is going to take my word about my altimeter on any given flight?

Thankfully, I have a functioning 15-year old Colibri logger, which still works just fine. It has a piezo pressure transducer, rather than GPS altitude.. The Colibri altitude read-out typically agrees with my altimeter within about 200'. For any flight where I come close to airspace boundaries, I use the Colibri to file my OLC flight claim. A public OLC record of my flight could be used as evidence, in case anyone claims that I violated airspace.

The old Colibri loggers were very useful for a couple of us at the Cowley, Alberta 2018 summer camp. Conditions were excellent, with many high altitude and long distance XC flights. But it can be quite challenging to legally navigate all the airspace restrictions in the Cowley vicinity and north to Calgary, Alberta.

So that's my fix for this issue. Cheers!
Roy