Ownship Icon pointing wrong

[gordonwhite96]

Brand new to Skyview, so maybe this is a noob question or a simple setting. But the airplane / ownship icon is at an angle, not pointing up like the track line.

 

[Danerazz]

That looks like you are sitting on the ground. Are you moving? Did you fly?

If stationary, the gps can detect movement in ANY direction, just enough to say “you’re moving that way” but the magnetometer knows which way you are pointed. The airplane symbol points to the actual heading. The track line is the actual movement.

This can be changed between “north up” and “track up” in the map setup menu, map mode.

Looking closer, you appear to be moving. If so, there is either a huge crosswind or your magnetometer is way off.

 

[gordonwhite96]

Thanks. This was in flight.

 

[Danerazz]

I edited my above post, it may now address your issue.

Does the magnetic heading seem correct on known headings?

 

[gordonwhite96]

Good question. It is roughly correct. I can double check on the next flight.

 

[gordonwhite96]

You might be on to something. Looking at the bigger picture, the PFD has a heading of 145, while the map has a heading of 079. If the magnetometer is way off, what’s the fix?

 

[gordonwhite96]

I'm now reading that there is a ground and in-flight calibration for the magnetometer. I haven't done that yet.

 

[Danerazz]

The map image is not a heading of 079, it is a track of 079. The airplane icon is pointing to the heading.

The map is in “track up” so the ground track will be vertical at all times, regardless of heading.

The two displays look like they coincide.

I’d do the calibrations.

Of note: the PFD image bottom left corner shows the wind indicating 209* at 99 knots. It uses magnetic heading, ground track, and airspeed to calculate the wind. If one of those is inaccurate the wind will be off significantly.

Either the wind was crazy, or your heading info is inaccurate.

I’d repeat the on-ground calibration in the install manual (exactly as it says: ready to fly, engine running), then make sure to do the inflight calibration as well. It states a minimum accuracy of 70 is required, closer to 100 is better.

 

[PaulSS]

The wind is crazy because the poor computer doesn't know the heading. In flight calibration is easy and will solve this problem.

 

[gordonwhite96]

Had a bit of time before work today. Did the ground and inflight. Improved, but still off. Airplane pointing a different direction now and with less crazy winds. I'll try the compass calibration again in a couple of days after my conditional inspection is completed. Thanks for the ideas.

 

[Danerazz]

What is the accuracy indicating (%) in the in-flight calibration menu?

How are you doing the ground calibration? Engine running? Calibrated compass rose? What is the heading indicating when you line-up on the runway? Anywhere close to the actual runway heading?

And: how is the magnetometer installed? Where is it installed? Is it properly lined up with the longitudinal axis? Or is it turned 90*? The cable exit on the device must be pointed to the nose, and it must be upright. This issue kind of looks like the magnetometer is mounted 90* off or some other installation error.

Is the hardware mounting it non-magnetic? Is there any steel structure near it? Use brass hardware (no steel washers or nut plates).

There is a note to not use magnetic tools (screwdriver) when installing because it screws-up the factory calibration.

It could be a bad magnetometer, but I’d carefully check everything else first. If it is not the magnetometer a replacement will have the same issue.

What kind of aircraft?

 

[gordonwhite96]

Ground calibration was engine running, iPhone compass. Not sure about runway heading, I'll check again as soon as I'm able to fly.
Given that my conditional starts today, I'll inspect to see how the unit is installed and try to get a picture. I know the installer had to shim the mounting to get the roll axis to be level. It also appears to be nose-low. They did not install the remote magnetometer.

Vans RV-6a.

 

[Danerazz]

The plot thickens…

The ADAHRS has the same magnetic issues if it is used for heading info. It must be free of magnetic interference. Steel structure or hardware nearby is an issue.

You might have to move the ADAHRS or install an SV-MAG in a remote location.

Again, test all of the installation before throwing parts at it.

 

[gordonwhite96]

Well, shoot. I couldn't wait, so I went to the hangar at lunch and pulled the floor panels. When the installer said he mounted the ADAHRS under the pilot's seat...he meant remote magnetometer. So yeah, here's a picture of where it is mounted. Right under the pilot stick. I can guess what you are going to say about this location. All of the software is on 16.4.6.10205, so I'll upgrade everything tonight or tomorrow. (This explains why the autopilot panel does nothing in simple mode...). I don't see any release notes on the magnetometer, so I fear a reposition is in the diagnosis.

 

[Danerazz]

You could disconnect the SV-MAG and see if the ADAHRS internal works better. Just note: if you disconnect you have to go through the component discovery process in the setup menu so it knows not to look for it, or it won’t enable the other magnetometer.

 

[gordonwhite96]

I was thinking the same thing but would have missed the discovery process...pro tip! Thanks!

 

[gordonwhite96]

Updates! First, I discovered the GPS was configured as the GPS-250 instead of the GPS-2020. Fixing that solved a few issues.

I disconnected the remote magnetometer, rediscovered the network, did a ground + air calibration. I'm *much closer, but not perfect. Maybe 10-15 degrees off instead of 45. It's actually pretty good on the ground.

I think next I'll retry the calibration at an airfield with a lot of room, but I'm leaning towards relocating the remote mag to the tail. Does anyone object to this location? (Van's RV-6a)
View attachment IMG_3338.JPG

 

[Stevec]

Check it with a hand compass. You will soon see if there is any major magnetic interference. My 6 does not have a remote mag I just use the one in the adhrs which is mounted behind the baggage bulkhead.

 

[gordonwhite96]

Thanks Steve. Do you have a picture of your shelf behind the baggage bulkhead?