Oregon 450 Altitude in airplane

[KbdKid]

I am having an issue displaying the correct altitude while flying in a pressurized airplane. I have turned off Auto Calibration and I have the barometer mode set to Fixed Elevation. The tracks contain the correct altitudes, but what is displayed is somewhere between 6000 - 8000 ft. I am assuming cabin pressure is being displayed. If I do a manual calibration and enter no for known pressure and no for known altitude, then the correct altitude is dispalyed for about 90 seconds and then the unit reverts to displaying 6000 - 8000ft.

 

Anyone have any suggestions on what I am missing? I would like to be able to see on the display the correct GPS altitude. Thanks!

Edited September 17, 2010 by KbdKid

[+PDOP's]

See question 3 at http://garminoregon.wikispaces.com/Altimeter

[KbdKid]

See question 3 at http://garminoregon.wikispaces.com/Altimeter

 

Thanks for the reply...I have looked at the wiki and the tracklog is correct. The issue I am having is on the display in real time. The display shows incorrect elevation.

[+Styk]

How do you know if you are displaying the correct altitude? I did not think cabin pressure followed the actual outside pressure otherwise there probably would be no point in pressurizing the cabin.

[+PDOP's]

Thanks for the reply...I have looked at the wiki and the tracklog is correct. The issue I am having is on the display in real time. The display shows incorrect elevation.

From the wiki

 

A2.) When I display elevation on the Garmin Oregon what am I seeing? GPS elevation, Altimeter elevation or DEM elevation?

 

With two exceptions: 1) the Satellite page which shows GPS elevation and 2) selecting a point on the map page which shows DEM elevation all of the elevation related data fields are based on the altimeter elevation....

[eaparks]

Unless something has changed with some software updates the only way to see the actual altitude (Mean Sea Level) in real time on Garmin GPSs that have the built in barometer in aircraft with a pressurized cabin is to view it on the "Satellite" page. The actual altitude can be recorded with the track but you won't be able to view it in real time. AFAIK this applies to all of the Garmin handhelds that have the built in barometer, 60CSx, 76CSx, Vista HCx, Colorados, Oregons, etc.

[KbdKid]

Unless something has changed with some software updates the only way to see the actual altitude (Mean Sea Level) in real time on Garmin GPSs that have the built in barometer in aircraft with a pressurized cabin is to view it on the "Satellite" page. The actual altitude can be recorded with the track but you won't be able to view it in real time. AFAIK this applies to all of the Garmin handhelds that have the built in barometer, 60CSx, 76CSx, Vista HCx, Colorados, Oregons, etc.

 

Thanks for the reply, this makes sense. The only odd thing I've noticed is that if I go thru the altimeter recalibration setup (setup -> Altimeter -> Begin Cal -> NO to correct elev -> NO to correct pressure -> YES to use current altitude) for about 90 seconds the compass screen displays GPS elevation (32,000 ft) and then switches back to what I assume is barometric elevation (~6,000 ft.)

 

At any rate, thanks for the info. I will use the Satellite page to view elevation on my next flight!

[+Mineral2]

I've noticed this problem too. Seems like Garmin could easily add an option in the unit's software to display altitude from the gps signal or the barometer for this purpose. But maybe they don't to dissuade the use of GPS devices on flights?