AV-30-C vs regular vacuum DG

Rebel Lord said:
Hey, my vacuum system failed a few weeks ago so I’ve been doing all my hood training partial panel. I’m for sure going with dual AV-30s and an av-20 for the right seat and ripping out the vacuum system. Got quoted $3500 for install, is that reasonable?
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That seems a bit high, but prices vary regionally so maybe it's reasonable for your area?

Spencer at KPLU did mine the same thing for me 1 year ago. Make sure to include the temperature probe (Davtron C307PS). Total cost (parts, labor, tax, etc.) was $6.1k. The AV-30 units were $2k each back then. As for the labor... Their quote included 2.5 hours to remove the vac system and 8 hours for the installation. Total labor about $1300. That didn't include the external magnetometer, which I'll add soon (already have a new one in a box). But that's probably only going to be a couple of hours.
 
Adding a magnetometer might be more than you think. Have to fabricate a new D sub harness with 3 conductor shielded cable, mount the sensor, fish the cable, flash new firmware, and calibrate the sensor. I can see that taking most of a day, especially if the AV-30 harnesses were not prepared in advance for flashing.
 
BTW, the AV-30C does have a built-in internal magnetometer (early units didn't but mine does, and it's a year old). Problem is, it's built into the unit, which puts it in the panel, which has plenty of electromagnetic fields from radios & such. That's why external ones are installed out in the wing. I've enabled and calibrated mine to try it, and it doesn't work any better (nor any worse). But this is airplane-specific so it may be worth trying before spending the money on the external one.
 
I was just watching the uAvionix update video for software version 2.4.1. They added a feature to trim the low and high airspeed for a more accurate reading.
Link: Check Out Version 2.4.1
uavionix.com

Open Connected Cockpit - uAvionix

Delivering simple, efficient avionics and services that offer you a choice of configuration, integration and interoperability
uavionix.com uavionix.com

They show the feature at about 8 minutes in the video
 
To their credit, uAvionix is always improving/updating the firmware. In my 172 the speed/AoA difference between slow and fast cruise is not enough to need separate trim settings. I have the pitch trim set so that the AI reads dead center at normal cruise speed (about 120 kts).
 
farangutan said:
but the AV-30s are capable when they're working properly and its limitations understood.
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If you have to write that it says everything. These are instruments that literally mean life or death. I would spend an extra $3000 and upgrade to the Garmin.

I’ve flown AV-30 without the magnetometer, and the precession was terrible. Nice UI tho.
 
Ed Haywood said:
Initial test flights with my restored Decathlon show the AV-30C performs fine in AHI mode. Once I finish engine break-in and start flying acro, I'll post some videos of how long it holds orientation during extreme attitudes, and how long it takes to recover.
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I did 2 consecutive reverse cuban 8's today (four halfs) and the AV-30 held orientation in AHI mode throughout.
 
Daleandee said:
OK that explains it. I'm looking at the experimental unit but I'm gonna add the magnetometer if/when I do.

I'm sure you know that there is a Wi-Fi connector available so that it's easier to do updates (listed as only allowed for experimental installs):

allavionics.com

uAvionix AV-Link WIFI Hub for AV-30E – AllAvionics.com

uAvionix AV-Link is a WiFi module companion to the AV-30E. AV-Link connects to a supported ADS-B Receiver, and displays live ADS-B traffic.
allavionics.com allavionics.com
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I just updated my firmware yesterday. I wasn't difficult.

15 pin solderless connector" has screws to tighten wires, and snaps together.

9 pin side:

9-pin to USB: (the one recommended by uAvionix)

Power supply (or just use a 12v battery)

Just follow the instructions for pin numbers from video on uAvionix's website. Very clear and easy to follow.

1703731145042.png


I think my unit was 2.1.x before I updated. Version 2.3.9 has a lot of interesting updates. There are a lot more trim settings.
 
rickgn said:
I just updated my firmware yesterday. I wasn't difficult.

15 pin solderless connector" has screws to tighten wires, and snaps together.

9 pin side:

9-pin to USB: (the one recommended by uAvionix)

Power supply (or just use a 12v battery)

Just follow the instructions for pin numbers from video on uAvionix's website. Very clear and easy to follow.

I think my unit was 2.1.x before I updated. Version 2.3.9 has a lot of interesting updates. There are a lot more trim settings.
Click to expand...

I was going to modify my installed harness with a permanently installed 9 pin dsub so that I could do future updates without removing the unit from the aircraft. Seems like uAvionix has a habit of frequent version updates. But maybe going this route and doing a bench harness is quicker and easier. I will probably just use crimped pin dsubs.
 
I recalibrated my AV-30c this weekend. The new software update 2.3.9 has a lot of new settings. I took the time to calibrate everything, not just the new stuff.

Now when I do a 180 degree turn, the internal magnetometer holds within 2 degrees of actual. Not bad. Being that there was a crosswind, it's difficult to say if the 2 degrees is real or not. It might actually be spot-on. I'm sure the external magnetometer is even better. I haven't installed mine yet. Just getting it prepared now.

* Adjusted the altitude on the low side but haven't done it on the high side. Still, it holds better now than previously.

* Recalibrated the pitot/static zeroing. The updated installation manual says that the pitot/static and the vibration calibration drifts as well and it should be periodically redone.
* Adjusted the slip trim.
* Adjusted the OAT. Apparently the OAT can drift over time, so it should be checked for accuracy occasionally.

I'm looking forward to the high/low airspeed trim in software version 2.4.x. If I calibrate at 95 IAS (my best climb speed) I'm off by about 3 knots at 150 IAS as compared to my analog indicator. It's only 2% difference so not too bad.

.. note that if your airplane does only 115 IAS you probably won't notice any difference with the high/low airspeed trim. I only noticed the difference starting above 110 IAS.
 
rickgn said:
I recalibrated my AV-30c this weekend. The new software update 2.3.9 has a lot of new settings. I took the time to calibrate everything, not just the new stuff.

Now when I do a 180 degree turn, the internal magnetometer holds within 2 degrees of actual. Not bad. ...
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I did the same with mine after first installed just over a year ago. Went through the menus and calibrated everything. This reduced drift to a manageable level, about the same as a mechanical gyro. But it still has one fatal flaw: temperature sensitivity. If you fly into temperatures significantly colder than when you started the engine (for example taking off at sea level then climbing above 10,000'), the AV-30 drifts like crazy to the point of being unusable. I haven't found any fix for that, reported it to uAvionix who says it's "normal". So I bought the magnetometer and will get it installed at the soonest availability for my local shop.
 
Finally got around to updating firmware so it recognizes my AV Mag. Updated to 2.4.1. No drift on test flight.

I wound up doing an update harness to fit between the instrument and aircraft harness, per the diagram on the last page of the most recent install instructions.

IMG_20240206_195125.jpg
 
Ed Haywood said:
Finally got around to updating firmware so it recognizes my AV Mag. Updated to 2.4.1. No drift on test flight.

I wound up doing an update harness to fit between the instrument and aircraft harness, per the diagram on the last page of the most recent install instructions.

View attachment 125150
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Is this harness permanently installed in the plane? We need to make our own and I'm curious if we need to get the most flexible guy in the club (me) to contort to get under the panel every time a new update rolls out.
 
farangutan said:
Is this harness permanently installed in the plane? We need to make our own and I'm curious if we need to get the most flexible guy in the club (me) to contort to get under the panel every time a new update rolls out.
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Mine is removable. It fits in between the instrument and the aircraft harness. Access is easy for me.
PXL_20240204_192802319.jpg
But you could fabricate an aircraft harness with a DB9 update connector built in, and just connect the USB adapter when necessary.
 
John Spartan said:
If you have to write that it says everything. These are instruments that literally mean life or death. I would spend an extra $3000 and upgrade to the Garmin.

I’ve flown AV-30 without the magnetometer, and the precession was terrible. Nice UI tho.
Click to expand...

Good luck with Garmin. :confused:

pilotsofamerica.com

Garmin G5 Yellow Heading & Warranty Saga (retitled)

4/15/2024 update: Problem solved. See https://pilotsofamerica.com/community/threads/garmin-g5-yellow-heading-warranty-saga-retitled.146190/page-3#post-3509076 Original post below… — What a nightmare. My avionics shop installed dual Garmin G5’s for me in early October 2023. Ever since the...
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I concur with the AV-30/AV-MAG experience some have. The one set as DG was terrible before the AV-MAG came out (with version 2.3.9). Precession went away but the AV-30s would keep indicating NOMAG often and was pretty frustrating. With firmware 2.4.1, the NOMAG indication has completely resolved and the DG works great. I see today the AV-HSI has been approved for experimental aircraft. Super excited for the STC version to come out by the end of this year! :)
PA-28-180 (1972)
 

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One issue I am beginning to see more often is a drift/lag in the AV-30 Attitude Indicator in turbulence. The AI shows a tiny/slight bank and takes a while to recover. Looking outside, the horizon is pretty stable. Inside, however, the AI shows a tiny bank. Anyone see this too?
 
Gaurav Dogra said:
One issue I am beginning to see more often is a drift/lag in the AV-30 Attitude Indicator in turbulence. The AI shows a tiny/slight bank and takes a while to recover. Looking outside, the horizon is pretty stable. Inside, however, the AI shows a tiny bank. Anyone see this too?
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The AI calibrates itself when you first turn it on. If the airplane is parked on a non-level surface, the AI will get a false horizon. It will adapt to that and shift back to normal, but it will take several minutes.

Parking on a non-level surface is more of a problem for the DG. It will drift faster than it should and it won't adapt or adjust until it is shutdown and restarted.

Generally, the AI measures acceleration directly, so it is more robust and doesn't drift. The DG is indirect, as it must integrate acceleration measurements to a heading. This makes the DG less robust, more sensitive to calibration and prone to drift.
 
MRC01 said:
The DG is indirect, as it must integrate acceleration measurements to a heading. This makes the DG less robust, more sensitive to calibration and prone to drift.
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Once you install the magnetometer, the DG is rock solid, zero drift in my experience.
 
Ed Haywood said:
Once you install the magnetometer, the DG is rock solid, zero drift in my experience.
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Agreed.. The DG is pretty good - maybe just a constant rocking of the heading +/- 5 degrees in flight. I have the AV-MAG. The concerning behavior is from the Attitude indicator which takes time to return to level. Concerned how it would be in IMC.
 
Gaurav Dogra said:
Agreed.. The DG is pretty good - maybe just a constant rocking of the heading +/- 5 degrees in flight. I have the AV-MAG. The concerning behavior is from the Attitude indicator which takes time to return to level. Concerned how it would be in IMC.
Click to expand...

I have been meaning to fly an aerobatic sequence in my aircraft with a Go Pro camera to show the AI drift. It keeps up for most of a 10 maneuver sequence, but falls behind at the end. Rolls freak it out, but it resets in 5 to 10 seconds. If you are concerned about using it in the soup, I would suggest getting some hood time with a safety pilot to see how it performs in reality.
 
Ed Haywood said:
Once you install the magnetometer, the DG is rock solid, zero drift in my experience.
Click to expand...
I got my magnetometer installed last week. Rock solid. I find it to work better than the standard compass because there is no lag/lead during turns. Accuracy is about +/- 2 degrees. There is no drift -- unlike a DG.
 
A little off topic but hoping someone can point me in the right direction. A couple years ago I installed dual AV30C displays in my PA22-150, the main with an OAT probe so I can get TAS. Recently I’ve noticed that my TAS was reading lower than my IAS by about 7-8 mph. My OAT seems to be reading/sensing correctly. Response from Uavionix was to trim (adjust) the IAS to match the TAS. This advice makes no sense. The box simply calculates TAS based on IAS, OAT and pressure.

By the way, my IAS matches closely with my round dial ASI.
 
What was your OAT? What was your IAS and altitude?
 
Brad Marcum said:
A little off topic but hoping someone can point me in the right direction. A couple years ago I installed dual AV30C displays in my PA22-150, the main with an OAT probe so I can get TAS. Recently I’ve noticed that my TAS was reading lower than my IAS by about 7-8 mph. My OAT seems to be reading/sensing correctly. Response from Uavionix was to trim (adjust) the IAS to match the TAS. This advice makes no sense. The box simply calculates TAS based on IAS, OAT and pressure.

By the way, my IAS matches closely with my round dial ASI.
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I also installed mine a couple of years ago. The AI has been solid, though something similar happened to me about a month ago on a long x-country flight. The AI started showing wonky TAS and DA values, even though the OAT looked OK. I thought maybe something wrong with the air pressure line to the AI.
After the flight I recalibrated the OAT (only changed it by about 1* C) and ran a GYRO CAL. Neither of which should have fixed the TAS and DA values which were way off. But since then it's back to normal. :dunno:
 
You'd have to be at a low density altitude (30.xx altimeter setting, close to the ground) to get TAS numbers lower than IAS.
What AV-30 software version?
Put your numbers in this TAS calculator and see what you get:
www.omnicalculator.com

True Airspeed Calculator

Use the true airspeed calculator to calculate the true airspeed (referred to as TAS) for all aircraft.
www.omnicalculator.com www.omnicalculator.com
 
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