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How I can see pressure altitude sended by GTX
- Thread starter eld
- Start date
On one plane I have GTN650XI and altitude source SAE5-35, in navigation mode, I have not found information.
on second one with on G3X (V9.31), but on system information, I check on PFD item, AHRS and XPDR, I can't find pressure altitude
On AHRS I find temperature but no pressure.
On Xpdr, I find Mode and Code but no pressure.
Controler say: check your altitude source, but I have not found solution during the fly.
on second one with on G3X (V9.31), but on system information, I check on PFD item, AHRS and XPDR, I can't find pressure altitude
On AHRS I find temperature but no pressure.
On Xpdr, I find Mode and Code but no pressure.
Controler say: check your altitude source, but I have not found solution during the fly.
On reading this again, I see you have a GTX 33ES. Unfortunately it's not possible to see pressure altitude data for these units. However, the pressure altitude used by your transponder is indeed the same as the pressure altitude displayed on your PFD, which you can verify with a transponder test set.
Thanks for your reply.
on plane where I have only GTN650Xi, I can't see altitude transmiteed by SAE5-35, with gtx330 I can, when transponder is remote how we can see pressure altitude receive by transponder.
On second one I have 2 sources for altitude, I can't see the value when it's not AHRS, and when it's AHRS, source, I can't see value, except if I change Baro setting, (during approche, not a good idea to change)
on plane where I have only GTN650Xi, I can't see altitude transmiteed by SAE5-35, with gtx330 I can, when transponder is remote how we can see pressure altitude receive by transponder.
On second one I have 2 sources for altitude, I can't see the value when it's not AHRS, and when it's AHRS, source, I can't see value, except if I change Baro setting, (during approche, not a good idea to change)
Pressure Altitude
The transponder can get the PRESSURE altitude from a number of sources.
ADAHRS (EFIS), altitude encoder, encoding altimeter etc.
The STANDARD pressure altitude is received from an external altitude source, which is not adjusted for barometric pressure.
The altitude is sent from the source to the transponder directly.
GTN650 is NOT involved.
GTX330ES. Altitude reporting equipment order of precedence:
1) ARINC 429 Air Data Computer (label 203, if configured W/ALT) (25’)
2) ARINC 429 EFIS (label 203, if configured W/ALT) (25’)
3) RS-232 Fuel/Air Data Computer (if configured W/ALT.) (25’)
4) Parallel wire Gray Code input (100’)
5) Shadin Altitude Serializer/Encoder (100’/25’)
6) Icarus Altitude Serializer/Encoder (100’/25’)
Good luck
The transponder can get the PRESSURE altitude from a number of sources.
ADAHRS (EFIS), altitude encoder, encoding altimeter etc.
The STANDARD pressure altitude is received from an external altitude source, which is not adjusted for barometric pressure.
The altitude is sent from the source to the transponder directly.
GTN650 is NOT involved.
GTX330ES. Altitude reporting equipment order of precedence:
1) ARINC 429 Air Data Computer (label 203, if configured W/ALT) (25’)
2) ARINC 429 EFIS (label 203, if configured W/ALT) (25’)
3) RS-232 Fuel/Air Data Computer (if configured W/ALT.) (25’)
4) Parallel wire Gray Code input (100’)
5) Shadin Altitude Serializer/Encoder (100’/25’)
6) Icarus Altitude Serializer/Encoder (100’/25’)
Good luck
thanks, I am agree with all that, but it's GTX33ES, I havn't display on this transponder.
When controller say your report altitude is not correct, I want check what value is sended via GTX, but I can't.
Controller find 250ft offset.
I use GTN to command GTX33ES, I hope find the pressure value on info lru or like that, but notthing.
When I check on ground, it's ok.
it's still a shame not to be able to visualize the value that the remote transponder sends, it was practical on the gtx330 (no remote, with display)
When controller say your report altitude is not correct, I want check what value is sended via GTX, but I can't.
Controller find 250ft offset.
I use GTN to command GTX33ES, I hope find the pressure value on info lru or like that, but notthing.
When I check on ground, it's ok.
it's still a shame not to be able to visualize the value that the remote transponder sends, it was practical on the gtx330 (no remote, with display)
The pressure altitude that the transponder sends to the radar station is
always referenced to 29.92".
When you check altitude with the controller, please make sure that your
altitude window on the G3Xt is set to 29.92".
All other settings will give YOU wrong information about the transponder
performance.
Good luck
always referenced to 29.92".
When you check altitude with the controller, please make sure that your
altitude window on the G3Xt is set to 29.92".
All other settings will give YOU wrong information about the transponder
performance.
Good luck
Walt
Well Known Member
In the US the controllers altitude is automatically corrected for local baro setting. 29.92 setting would be uncorrected altitude.
it's the same in europe, during approche under 5000-7000, when you pass from flight level(1013hpa in europe) to QNH controllers have altitude corrected to local baro too.
I therefore come back to my initial question, how to see the value transmitted by the gtx, knowing that I do not have G3X on one or the other, I have 2 altitude sources, so I would like to know the value transmitted by either (if I cut the first sources)
on the 2 planes the question arises, in the first case, the GTN does not display it to me, in the second case either, unless I go to 1013 AND the source is the AHRS, therefore for the other source no value either.
How to do Mr GARMIN?
I therefore come back to my initial question, how to see the value transmitted by the gtx, knowing that I do not have G3X on one or the other, I have 2 altitude sources, so I would like to know the value transmitted by either (if I cut the first sources)
on the 2 planes the question arises, in the first case, the GTN does not display it to me, in the second case either, unless I go to 1013 AND the source is the AHRS, therefore for the other source no value either.
How to do Mr GARMIN?
PRESSURE ALTITUDE.
It is the indicated altitude calibrated for your elevation above the standard datum plane (a theoretical atmospheric level where the atmospheric weight is 29.92” Hg).
The altimeter, ADAHRS (in G3X) or blind encoder provides PRESSURE ALTITUDE data to the transponder, according to ISA. (29,92", 59F).
The transmitted air data label to the transponder is: 203.
In the EU this would be easy. Just fly outside of controlled airspace and set
the Altimeter to 29,92". Then ask ATC what altitude they read.
In the US you need a 29,92" day or climb to FL 190 to check altitude.
Or with two altimeters, set one to local QNH and the other to 29,92".
Then ask ATC what altitude they read.
Good luck
It is the indicated altitude calibrated for your elevation above the standard datum plane (a theoretical atmospheric level where the atmospheric weight is 29.92” Hg).
The altimeter, ADAHRS (in G3X) or blind encoder provides PRESSURE ALTITUDE data to the transponder, according to ISA. (29,92", 59F).
The transmitted air data label to the transponder is: 203.
In the EU this would be easy. Just fly outside of controlled airspace and set
the Altimeter to 29,92". Then ask ATC what altitude they read.
In the US you need a 29,92" day or climb to FL 190 to check altitude.
Or with two altimeters, set one to local QNH and the other to 29,92".
Then ask ATC what altitude they read.
Good luck
Thanks for your reply, yes I have make this test, set
the Altimeter to 1013hpa, I have no issue.
During approche, I have the value from the controllers (offset 250ft).
I try to find a solution to see on my plane, what value the transponder receive from my 2 sources, because during fly in fly level I have no issue, it's only during approche.
On GTX330 I can check on transponder display,
now on my new transponder (remote GTX33ES) I try to find the value transmited.
During issue I have GTN650XI and altitude source SAE5-35.
the Altimeter to 1013hpa, I have no issue.
During approche, I have the value from the controllers (offset 250ft).
I try to find a solution to see on my plane, what value the transponder receive from my 2 sources, because during fly in fly level I have no issue, it's only during approche.
On GTX330 I can check on transponder display,
now on my new transponder (remote GTX33ES) I try to find the value transmited.
During issue I have GTN650XI and altitude source SAE5-35.
