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  #1  
Old 04-23-2017, 09:50 AM
zilik's Avatar
zilik zilik is offline
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Default G5 attitude indicator has a mind of its own.

I recently installed a G5 in my aging panel to replace a failing vacuum AI. The G5 was an easy choice as a G3X upgrade is in the future.

Installation was straight forward and easy as was the calibration. A test flight has me scratching my head.

On normal takeoff, straight out with gentle climb the G5 "aligned" itself many times. Granted the air was not smooth but I did not expect the constant "alignment". After about 5 minutes it seemed to have settled down and would show level flight.

Turns about a point, climbs, descents and S-turns all caused the unit to display a descending left turn with the occasional climbing turn after returning to level flight.

The slip/skid ball is not very sensitive. A full skid moves the ball very little while the analog slip/skid in the Trio is all the way to the left.

I turned everything off to see if electrical gremlins were causing the problem. No difference that I could notice.

Needless to say the AI is not to be trusted in this particular instrument. I returned to base, reset to factory defaults and went through the setup and calibration once again. The results were no different. the AI has a mind of its own.

I guess the next step is to upgrade the firmware and try again.
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  #2  
Old 04-23-2017, 10:00 AM
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Ironflight Ironflight is offline
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It sounds like a seismic event to me Zilik.....
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  #3  
Old 04-23-2017, 10:01 AM
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If you have not updated the firmware, do that first. There have been many revs to the firmware since release and one cannot assume that a new unit will have the lastest preinstalled.

I would give that a shot and try again.

My G5 is rock solid even while performing some test that can drive poor performing AHRS's crazy.
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  #4  
Old 04-23-2017, 10:15 AM
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You funny Dye. I'm off to Staples for the required Micro-SD card for a software upgrade.
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  #5  
Old 04-23-2017, 10:23 AM
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Brantel,

Can you expand on your testing of your other poor performing AHRSs as noted below?

My G5 is rock solid even while performing some test that can drive poor performing AHRS's crazy.[/quote]
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  #6  
Old 04-23-2017, 03:25 PM
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Quote:
Originally Posted by Brantel View Post
If you have not updated the firmware, do that first. There have been many revs to the firmware since release and one cannot assume that a new unit will have the lastest preinstalled.

I would give that a shot and try again.

My G5 is rock solid even while performing some test that can drive poor performing AHRS's crazy.
Armed with my macbook I headed to the airport. I updated the software and went for a flight. Loops, rolls, climbs, descents and stalls and the G5 performed flawlessly. Time to land and call it good.

A 5 mile straight it and the G5 started to roll in a left bank. Once I touched down the bank indication continued until I turned off the runway. Darn.

I pulled it and brought it home. Hopefully a call to Garmin in the morning will set it straight.
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  #7  
Old 04-24-2017, 08:16 AM
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Quote:
Originally Posted by strahler13 View Post
Brantel,

Can you expand on your testing of your other poor performing AHRSs as noted below?

My G5 is rock solid even while performing some test that can drive poor performing AHRS's crazy.
Mostly simple wringing them out....

Some things I like to do:

Turn them upside down for an extended period to see what happens, same for turning them 90°.
Sustained 60° + banked turns and then roll wings level.
Sustained high pitch then level out.
Observe how far behind the RV7 roll rate they get if at all, do they saturate or not with mild aerobatics, if they do, do they require realignment?
How fast they realign in various conditions IE: Vibration, speeds, pitch and roll angles etc.
Fly around with variable amounts of yaw with no roll and see what happens to the pitch and roll indications.
See how much yaw couples with roll on the ground by S turning.

Stuff like that. Not very scientific.

The poor performers are typically what I call "consumer" AHRS units that are not really intended to be a primary source of attitude information.

Since my testing is very personal in scope/intent and not very scientific, I will refrain from making any claims good or bad against any makes and models other than to say my G5, GSU73 and GSU25 have been rock solid units.

I am confident that TeamX will take care of Gary. I would imagine that Steve has already contacted him offline. That just just the way they roll....
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---------------------------------------------------------------------
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Last edited by Brantel : 04-24-2017 at 08:21 AM.
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  #8  
Old 05-01-2017, 08:52 PM
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Quote:
Originally Posted by zilik View Post
Hopefully a call to Garmin in the morning will set it straight.
Hi Gary,

Any feedback from Garmin yet? I've got a G5 in my panel waiting to be flown and your experience has me interested - not concerned yet, just interested.

Dave
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  #9  
Old 05-01-2017, 09:42 PM
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I had similar issues with my G5, until I updated the software. Since then (about 50 flight hours) I've only had one issue with it losing its mind, and that was in sustained moderate turbulence after about 20 minutes. I climbed high above the turbulence and it realigned itself a few minutes later.
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  #10  
Old 05-02-2017, 07:58 AM
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Quote:
Originally Posted by Brantel View Post
Mostly simple wringing them out....

Sustained 60 + banked turns and then roll wings level.
Hey, I know that trick, and the ahrs that didn't like it! .
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