Compass override

[skyboy999]

I'm having great difficulty achieving an acceptable compass calibration in my (steel framed) aircraft.

I understand that I could fit a separate magnetometer which would override the ADAHRS but fear I would have the same problem finding a magnetically benign location to install that also.

However, I understand that if I did install a magnetometer and this was subsequently u/s then SV would automatically fallback to using GPS as its 'compass' source...

So, my question is whether it is possible to configure SV to utilise GPS instead of ADAHRS as an option regardless?

I can appreciate the purist argument but could live with this for VFR flying...

Thanks

 

[Dynon]

There isn't a way to configure the system to work this way, though that's an interesting idea. SkyView expects to have a usable magnetic heading source in either the ADAHRS or magnetometer. Note that there some other features that won't work properly if you don't have real magnetic heading, such as winds aloft.

 

[skyboy999]

Thanks for reply. I note less sophisticated EFIS systems only use GPS so think it would be a useful configuration option to offer. Could you log as a suggested upgrade? Thanks again.

 

[dynonsupport]

For day VFR in the USA, there are no equipment requirements on most airworthiness certificates. However, for Night or IFR, you generally need to be equipped per 91.205, which requires a Magnetic Compass. So if you want to fly the plane at night, you do need a display of magnetic heading. Something to consider.

 

[swatson999]

For day VFR in the USA, there are no equipment requirements on most airworthiness certificates. However, for Night or IFR, you generally need to be equipped per 91.205, which requires a Magnetic Compass. So if you want to fly the plane at night, you do need a display of magnetic heading. Something to consider.

*Standard* airworthiness certificates include compliance with 91.205 for day VFR, as well. *Experimental* AWs don't, IIRC.

You need a *magnetic direction indicator* .  Fortunately, the SV system meets that definition, right, Dynon?

Some Luddite DARs and FAA inspectors don't understand this still, however, and keep insisting that it has to be a "wet compass".  They're wrong.  Make sure yours knows what's what.

 

[dynonsupport]

Unless you have managed to get pretty odd operating limitations, the limitations for EAB in the USA almost always say:

"The aircraft is restricted to Day VFR only UNLESS equipped per FAR 91.205."

Yes, the Dynon magnetic indicator meets the requirements of 91.205. It would not if we replaced it with GPS data, and I was just pointing out that it's not as simple as IFR/VFR, it's even night VFR that requires the magnetic direction indicator per almost all operating limitations. So if we take it off the EFIS, you need to go install a wet compass for night flight.

 

[swatson999]

Yes, you were correct *for EABs*. I was only pointing out that "most" was a little imprecise, as for non-EABs, 91.205 applies.

As for magnetic direction indicators...I was very glad my DAR had zero problems with an EFIS-based indication. I've heard horror stories of DARs "requiring" all sorts of crazy things (the least of which is a wet compass!)

 

[skyboy999]

Caveats previously acknowledged guys. I was only suggesting GPS as a configuration OPTION to override ADAHRS compass and still think this has much merit for experimental a/c flying day VFR...