I have noticed on the simulator and when flying if I put the mode switch in Attitude it says no GPS.  However if I select RTH it seems to use the GPS function to return home.  If the GPS was actually lost and not functional will the aircraft be able to find its way back to the home point or are you totally on your own.
Seems like a important point if you are flying far enough away that you can still see the aircraft but not be able to determine its orientation relative to you.
Same question with Course Lock set....can you pull it back to yourself or not, if GPS fails.
At long distances you can use the direction indicator (red arrow) on the map to orient your aircraft....does this still work if GPS shuts down?
It is my understanding on the V2+ that the RTH will auto function if the Tx is shut off, or, the connection is lost.....does the Inspire do the same thing?  
What I'm looking for is how to get your aircraft back if you are far away and cannot tell the orientation of your bird and your GPS fails.
A friend and I lost a Nano QX a couple months ago.  He is an experienced RC pilot but had never flown a quad copter before.  Before we knew it he had the nano so far away we couldn't determine its orientation.  I grabbed the controls but it was to late...I couldn't get it back either.  That was only a $70 lesson....the Inspire would be another thing altogether.
Any wisdom would be appreciated.

Hi Elliot,

As long as the Home Point is recorded before take off , the Inspire should to be able to Return to Home from an A mode flight.  Calibrate your compass too.    But since you fly already just pardon the extra information.  You can also switch between modes during flight.  Have you tried switching between modes during flight? Or have you not flown Inspire at all yet.  

As far as no live GPS reception but a controller link and visual of the directional 'radar' in the Pilot App I suppose that is the same as when you do so in Atti or any mode with a clear visual of the aircraft and good RC link.  Maybe Ed or someone can answer this.

Edit: As for your Course Lock question I can only go on what the manual says.  It indicates that GPS is not utilized/relied upon during that aspect of IOC whereas it is enabled/utilized/relied upon in the other IOC/F Mode functions like Home Lock and POI. Maybe someone else could elaborate on that or tell me if I'm confused.

PS: If I don't understand your questions just let me know.  I guess one thing you are asking is if when in Atti or any other mode  -- and then have a Failsafe or manual RTH event -- if the aircraft must rely solely on live GPS for RTH? And then what happens if there is weak or no satellite reception available, say, you are in a natural or urban canyon or something?   One question I do know the answer to is about the Tx failure; It is supposed to automatically RTH if RC signal is lost.   As for simultaneous failure of live GPS reception and of the link to controller..... Someone else here with more precise knowledge could probably answer that for you.

Dan

Note that there is an issue if the compass information is corrupted then the FC turns off the GPS.  During that period of time RTH is not possible as the craft has no GPS lock.  In normal conditions if you are flying in ATTI with GPS lock you can initiate RTH with no issues.

Thanks guys....just to be clear thenTahoe Ed...if the GPS actually goes down then RTH Failsafe will not work....is that correct?
Also if I am on CL mode can I still pull the Inspire back to me if the GPS is down.  In Course lock it doesn't matter what the orientation is you simply fly relative to the original course heading that was set.  Ed do you know if this the case?

Dan ....I looked up the CL in the manual and it does seem to indicate that CL return does not depend on a GPS reference.  I just want to be sure...I always set the CL before I fly thinking that at least if the GPS fails I can still toggle to CL and pull it back to me.  In C L mode it doesn't' t matter what the orientation is at long distance...the aircraft will respond to the right stick according to the original course grid setting.

ElliotTeskey Posted at 2015-2-3 03:17
Dan ....I looked up the CL in the manual and it does seem to indicate that CL return does not depend ...

Hi Elliot,

I believe Course Lock can work off of the IMU. The issue I would have using Course Lock from the kind of distances I think you may be talking about is that I'd lose orientation of my course line.  I'm sure there are many who would not.  I mean I'd need some visual of the aircraft. But that's just me. If you could do it that's good.   As far as losing GPS say from flares or obstructions or what have you,  it never really entered my mind while using Inspire as I've never lost the video stream when I have lost orientation of the running lights.  If I lose the Tx  I figure I likely have at least minimum satellite contact to RTH.  If I were to lose satellite then I figure I would probably have the Tx and camera visual and I will probably land where it is.  Also, if I lose the camera visual and craft orientation and also my travel path in the Pilot App but have GPS I could immediately hit RTH.    This could happen in a low light situation.  Also I would take a bit of comfort in the fact that this thing does land when it is out of steam and I've certainly given it plenty of tests in this regard.

Also don't discount the power of a pair of binoculars and a buddy as a good failsafe mode if you are flying off in less than perfect light.  I will use a friend as a spotting slave for such events haha.

And yes I believe you need 3D GPS for RTH unless these things get a bit more sophisticated and learn to function on 2D and/or some very sophisticated compass waypoint tracking system

daninperth Posted at 2015-2-3 05:57

And yes I believe you need 3D GPS for RTH unless these things get a bit more sophisticated and learn to function on 2D and/or some very sophisticated compass waypoint tracking system

Keep in mind that if a 2D GPS signal were to be used, there is no elevation information available.  It would strictly be horizontal control - you need at least four satellites for 3D mode.   Not sure how this would affect the operation of an RTH action but I can think of many reasons that it would be bad.