I saved my Air from RTHing away

[BudWalker]

Neither of those files appears to be a flight log. Did you select a flight control entry? The DAT file from the mobile device might be easier to find.

Those .DATs are from a Mavic Air which are encrypted. DatCon (and CsvView) can't process them - that's why the error message "... not a .DAT file" is issued.

 

[sar104]

Those .DATs are from a Mavic Air which are encrypted. DatCon (and CsvView) can't process them - that's why the error message "... not a .DAT file" is issued.

Of course. I knew that.

So the mobile device DAT file is the best and only solution in this case.

 

[laurens23]

When you got connection back the The GoHomeStatus was still in "Standby" I think it should have been in "Cruise". It looks like it might have just been stuck in "standby", drifting in the wind (I don't have a paid Airdata account to check the wind). Just speculation, but maybe a dirty obstacle avoidance sensor prevented it from going into "Cruise". Still the orientation is weird as well.?

Can you also upload the .txt from the successful flight? then we can compare them.

On my MPP GoHomeStatus is "Standby" during normal flight mode, and "Allign" or "Cruise" when in RTH mode. your was "Other" for the whole flight and "Standby" during the RTH.

 

[Epp1983]

I retrieved the DAT files from the aircraft using DJI assistant 2 as described here: How to retrieve a V3 .DAT File from the AC
I'm sorry you can't open them.
How do I get the DAT files from my mobile device?

 

[Keule]

How do I get the DAT files from my mobile device?

How to retrieve a V3.DAT from the tablet

 

[Epp1983]

How to retrieve a V3.DAT from the tablet

All the files on the specified folder are from Fabruary and March. I do no see the log for flights after that.

 

[Jameslavis]

Sar’s point about a previous homepoint makes sense. The app stores everything Inclucing coordinates.

 

[Epp1983]

Sar’s point about a previous homepoint makes sense. The app stores everything Inclucing coordinates.

If we assume that the aircraf was heading for a previous HP, it still doesn't make sense, as I never took off the aircraft in any position (or anywhere near) on that heading vector.
The only explanation I can come up with, is that somehow the aircraft was trying to retrace (roughly) the path back to the HP.
But I don't think they are programmed that way.

 

[msinger]

The only explanation I can come up with, is that somehow the aircraft was trying to retrace (roughly) the path back to the HP.
But I don't think they are programmed that way.

The Mavic Air does attempt to retrace the previous path for up to 60 seconds if the remote controller signal disconnects mid-flight. However, it should stop attempting to RTH if the remote controller signal reconnects within that 60 seconds.

 

[sar104]

The Mavic Air does attempt to retrace the previous path for up to 60 seconds if the remote controller signal disconnects mid-flight. However, it should stop attempting to RTH if the remote controller signal reconnects within that 60 seconds.

Interesting. Then I think that explains the aircraft's behavior completely - it did cease RTH on reconnect.

 

[Epp1983]

Interesting. Then I think that explains the aircraft's behavior completely - it did cease RTH on reconnect.

It did not.
I manually canceled it and brought the drone back.

 

[sar104]

It did not.
I manually canceled it and brought the drone back.

That's not what the log shows - the aircraft was stationary on reconnect.

Edit - disregard - wrong disconnect.

 

[Epp1983]

That's not what the log shows - the aircraft was stationary on reconnect.

Check 12m 54.3s (moment of reconnection).
Home distance keeps increasing till it leaves "Go Home" mode (when I manually canceled RTH).

 

[sar104]

Check 12m 54.3s (moment of reconnection).
Home distance keeps increasing till it leaves "Go Home" mode (when I manually canceled RTH).

Agreed - see my edit. I was looking at a different disconnect.

 

[Heshamp]

it is fail safe RTH ,the a/c started to fly the same flight pass before the signal disconect ,may be you fly it away first then return back so you turn RC off ..

 

[Donnie Frank]

Hey guys, yesterday was an experiment day.
I'm usually a believer of knowing the limitations of equiment. If you know what they are capable of you know what to expect from them.
I was a Mavic Pro owner for over an year I think I have tried every aspect of it.
Yesterday I decided to see the Mavic Air response to loss of connection.

The basics:
- No wind
- Constant LOS
- Home point set
- 60m RTH height
- No sensor errors (checked right before turning remote control off, and no issues while flying before the test)

I hovered the drone roughly 400 feet away from me at a height of 120 feet and switched off the remote.
After about 3 seconds the Air started climbing to the predefined RTH height. So far so good.
But then it turned to the oposite direction and started to move further away from the home point.
I immediatly turned on the remote and a little after I regained downlink.
Before canceling the RTH I checked the map to see if the home point had changed, and it had not.
The aircraft was indeed moving away from homepoint, and still no sensor errors.
RTH was then cancelled and I flew the drone back to me (the homepoint) for a successful retrieval.

After this incident, I popped a fresh battery and repeated the experiment under the same conditions and while hovering in the previous location (at the time I tought it could be some kind of magnetic interference at that location).
The drone executed the RTH correctly.

Now, this first RTH was pretty odd as everything was correctly set.
I've seen a couple of flyaway happening but usually they are due to pilor errors.

I'll leave the flightlog for you to check if you want to.
DJI Flight Log Viewer - PhantomHelp.com

Remote control off is at 12m 5s.
Downlink restored at 12m 54.3s.

Let me know your thoughts about this incident.
Thanks in advance.

Best regards,

Emanuel

Can you post your software and firmware versions?

 

[Epp1983]

Can you post your software and firmware versions?

App 4.2.8 (Android)
Aircraft 01.00.0300
RC 01.00.0100

 

[BerndM]

Hey guys, yesterday was an experiment day.
I'm usually a believer of knowing the limitations of equiment. If you know what they are capable of you know what to expect from them.
I was a Mavic Pro owner for over an year I think I have tried every aspect of it.
Yesterday I decided to see the Mavic Air response to loss of connection.

The basics:
- No wind
- Constant LOS
- Home point set
- 60m RTH height
- No sensor errors (checked right before turning remote control off, and no issues while flying before the test)

I hovered the drone roughly 400 feet away from me at a height of 120 feet and switched off the remote.
After about 3 seconds the Air started climbing to the predefined RTH height. So far so good.
But then it turned to the oposite direction and started to move further away from the home point.
I immediatly turned on the remote and a little after I regained downlink.
Before canceling the RTH I checked the map to see if the home point had changed, and it had not.
The aircraft was indeed moving away from homepoint, and still no sensor errors.
RTH was then cancelled and I flew the drone back to me (the homepoint) for a successful retrieval.

After this incident, I popped a fresh battery and repeated the experiment under the same conditions and while hovering in the previous location (at the time I tought it could be some kind of magnetic interference at that location).
The drone executed the RTH correctly.

Now, this first RTH was pretty odd as everything was correctly set.
I've seen a couple of flyaway happening but usually they are due to pilor errors.

I'll leave the flightlog for you to check if you want to.
DJI Flight Log Viewer - PhantomHelp.com

Remote control off is at 12m 5s.
Downlink restored at 12m 54.3s.

Let me know your thoughts about this incident.
Thanks in advance.

Best regards,

Emanuel

I'm happy you got your MA back OK.
Looking at your flight log, I saw you took off with 9 satellites, which should be OK
BUT there is nothing to show that your "Home point Recorded" on the log.
I think THAT may have been your problem

 

[Epp1983]

I'm happy you got your MA back OK.
Looking at your flight log, I saw you took off with 9 satellites, which should be OK
BUT there is nothing to show that your "Home point Recorded" on the log.
I think THAT may have been your problem

You are probably right.
Although, that being true there is a bug in the system.
The app clearly understood the HP as it showed the "H" on the minimap and the log correctly keeps track of home distance, but the aircraft somehow got confused.
Could this be due to low sattelite count? From what I understand 8 is the minimum, and I did had 9. Also I'm pretty sure I was in GPS mode at time of takeoff.

This raises the ultimate question: if according to all flight telemetry there was a homepoint recorded, how can any pilot be sure that the aircraft got it right?! I guess we can't.

 

[sar104]

You are probably right.
Although, that being true there is a bug in the system.
The app clearly understood the HP as it showed the "H" on the minimap and the log correctly keeps track of home distance, but the aircraft somehow got confused.
Could this be due to low sattelite count? From what I understand 8 is the minimum, and I did had 9. Also I'm pretty sure I was in GPS mode at time of takeoff.

This raises the ultimate question: if according to all flight telemetry there was a homepoint recorded, how can any pilot be sure that the aircraft got it right?! I guess we can't.

I thought that the conclusion was that the aircraft would retrace its path, rather than return directly to the home point. If you look at the location and heading of the aircraft at 774 s, when it reconnected, it was in exactly the same location as previously at 655 s, with a heading almost exactly 180° opposite. That strongly implies that it was retracing its route, and that there is no reason to suppose that it had not properly registered the home point.

The only remaining question is why it did not cancel the retrace after reconnecting, but you only gave it 4 s before canceling, assuming that you canceled rather than the FC - the log doesn't distinguish. I suspect that there is no problem here at all.