AOA calibration warning

[CurtisA]

We have been investigating the possible issues and bugs that may exist in the AoA calibration. I would like to start with hopefully clarifying how this system should work. For either of the AoA calibrations you will need an ADAHRS and an AoA capable pitot tube. If the aircraft has those two things it can calibrate its AoA. Once the aircraft is equipped with EMS and a flaps position sensor is installed and calibrated, the AoA menu will change to give the option to calibrate at different flaps positions. In doing the calibration with flaps it is important to not change flap position while doing the calibration for that slot. This is because each of the calibrations is saved in a table corresponding to flap position. The SkyView will load each of the calibration states based on where the flaps currently are.

For those facing the problem of NEED USER AOA CAL warning please contact support. We are attempting to track down this issue. Looking through this forum there was a screenshot posted by bruceh showing ADAHRS-04321 has NO PITOT PRESSURE CAL. I suspect this is what is causing the warning to occur for this user. One of the conditions to see the NEED USER AOA CAL warning is that one of the ADAHRS has a good calibration and one of them has a bad calibration. And the condition of NO PITOT PRESSURE CAL would be seen as a bad calibration.

For those who are facing a problem with the AoA stall sound never hitting a full stall. When doing the calibration, start the process of performing a stall. Once you hit the point in the stall where you would like the tone to be solid, level off the aircraft and push stall. This should help move the tone more inline with where you want it as the pilot.

 

[airguy]

For those who are facing a problem with the AoA stall sound never hitting a full stall. When doing the calibration, start the process of performing a stall. Once you hit the point in the stall where you would like the tone to be solid, level off the aircraft and push stall. This should help move the tone more inline with where you want it as the pilot.

That's what I did with my RV9A - I wanted the tone hard solid about 3 knots above the break. I flew a set of stalls and noted the break airspeed, then did the calibration routine and "told it" the stall was about 3 knots faster. That 3 knots belongs to me as the pilot. I want to hear that sound at an altitude of about 2" over the pavement, no other time.

 

[bruceh]

Bruce,
I have engineering looking into this and they would like to get diagnostic files from your system.

Let me know where to send them!
Flew yesterday and today. Same thing happens. I did a fast taxi and the caution warning audio happened multiple times. It has consistently happened just as I am accelerating for take off.

 

[CurtisA]

Let me know where to send them!
Flew yesterday and today. Same thing happens. I did a fast taxi and the caution warning audio happened multiple times. It has consistently happened just as I am accelerating for take off.

Once a log is exported from the EXPORT DYNON DIAGNOSTIC FILE it can be uploaded here https://www.dynonavionics.com/data-datalogs-upload.php

 

[bruceh]

I was given the link to download a release candidate to test a possible fix. I installed the update today, then went out to fly around a bit to warm up my engine oil (fresh from an oil change). Again, taxiing out I would get the audio "Caution" warning. This happened multiple times as I was taxiing.
I did manage to get a screen shot, and I did a diagnostic log dump, but I forgot to grab the USB stick to take home. I'll get that tomorrow and post.

So, I don't think 16.7 RC4 is going to solve this. I only hear/see the CAUTION warnings during taxi speeds under 20Kts. Above that it goes silent. The AOA tones work as expected when I get a high enough angle of attack during flying.

 

[Lee_Kitson]

I'm having the same issue. I installed V16.6 a week ago and test flew the airplane and everything was fine ( although I didn't do the AOA calibration for different flap settings yet). Yesterday I calibrated the AOA for 0, 10, 20 and 40 degrees but I didn't do the zero pressure IAS calibration before hand . After I did the AOA calibration I did a number of landings and the AOA warning tones didn't come on at approach speeds and didn't come on until roll out. Today I did the zero pressure IAS calibration and then took the plane out to repeat the AOA calibration. On taxi out I got numerous aural caution warnings and the yellow caution light would flash but the caution always cleared before I could read it. This happened repeatedly with a second or so between cautions. It finally stopped when I did the run up so I took off but it did happen once on the takeoff roll. I went up and did stalls at all flap settings and got good tones. I did recalibrate the 40 degree setting because I wanted the tone to happen at a higher airspeed. I did 4 landings at full flaps and was happy with the AOA tone airspeed. The caution did occur a few times while I was taxiing between landings.

After the flight I reviewed the alert file and found that the mysterious cautions were saying that the AOA needed calibration although they were clearing immediately.

Next flight I'll probably redo the AOA calibration for 0, 10 and 20 degrees since I didn't redo them after I did the zero pressure IAS. Hoping that will fix the issue.

BTW, I only have a single HDX screen so it doesn't appear to be a problem with syncing between screens

 

[porterjames]

I had been having the same problem, but with the new software update this issue has been resolved.

 

[bruceh]

I did update to 16.7 and the issue seems to have gone away. I've done at least 4 flights with the updated software and haven't had any "Caution" warnings. I have not gone into the settings and changed anything back after making a couple of changes as requested by Dynon.

 

[Lee_Kitson]

I flew with 16.7 yesterday and did a couple of landings. The issue seem to have been resolved.