What does not fail if GPS signal is lost?

[Solana]

Although there is a list in the Skyview manual showing what depends on GPS, I still am not sure that I can confidently describe what would be working, and how it would be working, if GPS signal was lost.

I get that you would lose: bearing, CDI, distance to waypoint, GPS altitude, ground speed, ground track, GPS approaches, time, waypoint identifiers, and wind.

I'm pretty sure I would also lose flight path marker and synthetic vision.

What I'm not sure of is attitude. It sounds like attitude is unaffected if your pitot and static are OK, otherwise attitude depends on GPS. Is that right?

Also, what about heading. It sounds like you would lose track information, but not heading. Is that right?

Thanks!

Rick Solana

 

[lancair360]

AHRS takes in pitot static info for advanced AHRS data, but not GPS data. You'd have attitude and airspeed/altitude but everything else you mention would be gone. You may be able to access the GPS database in the Dynon (direct KOSH) but it would know where you are so no nav.

 

[RV14_TD]

You'd have attitude and airspeed/altitude but everything else you mention would be gone

how about magnetic heading? Would that be gone too? Why?

 

[lancair360]

AHRS has a built in magnetometer (or you have a remote one installed) so nope, you'd still have heading

 

[Dynon]

This has been answered previously by Dynon on the old forum. I don't recall the exact wording but the system will use available information to estimate your location in the absence of GPS.

There isn't any position estimating without GPS. IE, SkyView doesn't fall back to any inertial type stuff for position - you need REALLY great sensors in an ADAHRS - the kind you'd find on an airliner - to be able to do that.

 

[lancair360]

Yeah our IRS on my work bird is good for 6 minutes minimum to get us out on a missed approach. We do a lot of mountain valley approaches so possible to lose GPS. Also provides info the HUD.