How accurate are garmin avionics?

After re-reading the original post I realized the following is probably irrelevant to the OPs question. And I like to complain about those who go off on a tangent.... However, since it's done, someone might get something out of it:

It's interesting you ask this question. On my homebuilt I originally installed an old style attitude indictor. I trusted that device after a couple of inadvertent IMC situations. Then it went TU and I went with a G5 (at half the cost of a certificated one which still makes no sense to me...).

I did not really trust the G5 for a long time. Not sure why, but I felt the need to frequently cross check data from my remaining steam gauges (VFR). I think part of my brain was struggling with the idea that there was so much data on a tiny screen, that something could be off. I actually regretted installing it for a long time because I didn't trust it, though I had no real basis for this.

After a lot of flights and some encounters with bad weather I've changed completely. The fact that in low vis or turbulent situations I can get everything I need to control the plane from that one tiny gauge. Again, I'm talking VFR situations here, not IFR.

Two weeks ago I got into some extreme turbulence (for my LS) and just being able to focus on that one gauge was a huge benefit.

Not exactly sure how "accurate" they are, but they are clearly accurate enough for me. After using my G5 for a while I wouldn't want to fly without one.
 
In my case NOT VERY ACCURATE...
Actually completely WRONG INFI displayed on my AERA 660!
If it was my only avionic to rely on I'll be dead on my first flight!
I am at 50'AGL 5 seconds after takeoff my AERA660 says I am at 850' AGL...
I am at 10 miles to my destination airport my AERA660 says I have 26.4 miles to go...
When my GS is 100mph it says I am doing 142mph while other indicators says I am doing 104 mph as my GS...
Ridiculous!
I've talked to Garmin support and they agreed to replace my 1 yr old unit with a rebuilt one and it does the same thing too and Garmin support have no idea what's going on!
I have ForeFlight working perfectly OK in my plane whether on my iPad or iPhone with 100% correct information while GARMIN 100% WRONG all the time!
Again, simply ridiculous!
 
In my case NOT VERY ACCURATE...
Actually completely WRONG INFI displayed on my AERA 660!
If it was my only avionic to rely on I'll be dead on my first flight!
I am at 50'AGL 5 seconds after takeoff my AERA660 says I am at 850' AGL...
I am at 10 miles to my destination airport my AERA660 says I have 26.4 miles to go...
When my GS is 100mph it says I am doing 142mph while other indicators says I am doing 104 mph as my GS...
Ridiculous!
I've talked to Garmin support and they agreed to replace my 1 yr old unit with a rebuilt one and it does the same thing too and Garmin support have no idea what's going on!
I have ForeFlight working perfectly OK in my plane whether on my iPad or iPhone with 100% correct information while GARMIN 100% WRONG all the time!
Again, simply ridiculous!
I’d say the certified primary instruments are very good. I use two 660’s: one as my “panel” in my gyro and one as an additional moving map for my Warrior (mainly for wx and traffic). Both of my 660’s have external antennas added. You may consider trying that. IIRC Garmin antennas aren’t terribly expensive but knock-offs on Amazon were in the $30 range (those are what I use).

Add: actually, I think I did go with the Garmin one for that and a knockoff for something else. The Garmin ones are $30 at Spruce.

IMG_6448.pngIMG_6448.png
 
would you pls let me know which aftermarket model you are using for your Garmin Aera 660?
 
In my case NOT VERY ACCURATE...
Actually completely WRONG INFI displayed on my AERA 660!
If it was my only avionic to rely on I'll be dead on my first flight!
I am at 50'AGL 5 seconds after takeoff my AERA660 says I am at 850' AGL...
I am at 10 miles to my destination airport my AERA660 says I have 26.4 miles to go...
When my GS is 100mph it says I am doing 142mph while other indicators says I am doing 104 mph as my GS...
Ridiculous!
I've talked to Garmin support and they agreed to replace my 1 yr old unit with a rebuilt one and it does the same thing too and Garmin support have no idea what's going on!
I have ForeFlight working perfectly OK in my plane whether on my iPad or iPhone with 100% correct information while GARMIN 100% WRONG all the time!
Again, simply ridiculous!

Did you check the GPS info page, it gives you satellite connections and accuracy estimate, if it loses connections its accuracy quickly degrades.
 
It has a knob you turn to set the temp vs alt, which moves a ring (white in the pix) to show TAS. Both the CAS and TAS on the steam gauge consistently read a few knots lower than the 275.

Yep - I was at 16K in my (180hp) Warrior. A solid endorsement for ElectroAir!

View attachment 129200View attachment 129199
yep, I got the similar setup with G5 as AI and the old style ASI.
 
In my case NOT VERY ACCURATE...
Actually completely WRONG INFI displayed on my AERA 660!
If it was my only avionic to rely on I'll be dead on my first flight!
I am at 50'AGL 5 seconds after takeoff my AERA660 says I am at 850' AGL...
I am at 10 miles to my destination airport my AERA660 says I have 26.4 miles to go...
When my GS is 100mph it says I am doing 142mph while other indicators says I am doing 104 mph as my GS...
Ridiculous!
I've talked to Garmin support and they agreed to replace my 1 yr old unit with a rebuilt one and it does the same thing too and Garmin support have no idea what's going on!
I have ForeFlight working perfectly OK in my plane whether on my iPad or iPhone with 100% correct information while GARMIN 100% WRONG all the time!
Again, simply ridiculous!
Most likely poor satellite reception due to device placement. Get a remote GPS puck and put it where it has an unobstructed view of the sky.
 
If the pilot can’t use the altimeter in the GI275 as primary (per the GI275 manual - see warnings) why would the pilot be able to use the airspeed indicator as primary?
The GI 275 is certified as primary for all the instruments, including airspeed and altitude. Were you speaking of the G5? That one is not.

There are no warnings regarding usage as a primary instrument in the current manual (Rev. P) for the GI275. But I still have a copy of Rev. A too, and it doesn't have those warnings either.
 
Back
Top