Van's Air Force
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GRT EFIS problem
- Thread starter pauldan181
- Start date
Looks like maybe an AHRS "failure".
Make sure that it is getting power.
Make sure no connectors to/fomr the AHRS were dislodged a little during g inspection.
Save a DEMO file of this and send to GRT. They will be able to tell you what is going on inside.
planenutz
Well Known Member
You have ASI and ALT as well as all the other numbers, but what you don't have is attitude reference data so it seems you've lost your connection to the AHRS as JCLARK mentions above. Whether this is due to an internal failure or whether this is a simple "plug" issue cannot be determined without a bit of simple troubleshooting.
I'd be checking your plugs to make sure they're all fully seated and the screws are tight. Check to make sure there is power going to the AHRS and make sure your ground wire is also secure. These are the basics you'll need to do in order to get started down the road to fully understanding the problem.
Sadly, I suspect your attitude reference board might be the issue because it seems you have power to AHRS box in order to deliver ASI and ALT signals from the Pitot/Static sensors.
Please be sure to post the results of your troubleshooting.
I'd be checking your plugs to make sure they're all fully seated and the screws are tight. Check to make sure there is power going to the AHRS and make sure your ground wire is also secure. These are the basics you'll need to do in order to get started down the road to fully understanding the problem.
Sadly, I suspect your attitude reference board might be the issue because it seems you have power to AHRS box in order to deliver ASI and ALT signals from the Pitot/Static sensors.
Please be sure to post the results of your troubleshooting.
clam
Well Known Member
Like the above two replies, I suspect wires dislodged during inspection. You may also consider removing the AHRS box and "gently" turning it upside down, sideways, etc. I was experiencing anomalies and found screws & nuts had become loose inside the box. I only found this by the "rattling" noise when moving the AHRS box. I opened the box, secured all the hardware, has worked as advertised since then.
Zuluzephyr
Member
GRT EFIS
The sub-D connectors sometimes need inspection and cleaning to improve signal transmission. Think of using a contact cleaner on the sub-D's.
The sub-D connectors sometimes need inspection and cleaning to improve signal transmission. Think of using a contact cleaner on the sub-D's.
pauldan181
Well Known Member
Update
I saw that my EFIS SW Ver. was 2 rev's behind so I updated the SW to the latest and after the auto re-boot the AHRS was still dead. The release notes did reference several AHRS fixes and I did update my NAV database during the CI and all was ok then. I then did a target load of only the AHRS SW and after power up all was well. I don't know if the full power down re-boot or the AHRS reload fixed this but seems OK now.
FWIW, this GRT system has been rock solid for 10 years now.
I saw that my EFIS SW Ver. was 2 rev's behind so I updated the SW to the latest and after the auto re-boot the AHRS was still dead. The release notes did reference several AHRS fixes and I did update my NAV database during the CI and all was ok then. I then did a target load of only the AHRS SW and after power up all was well. I don't know if the full power down re-boot or the AHRS reload fixed this but seems OK now.
FWIW, this GRT system has been rock solid for 10 years now.
