Mavic Pro takes off (and got lost) after iphone shuts down

[msinger]

Does the community think that hover could be a good option during a disconnect or would that only make things worse?

It works great when the Mavic is not flying in ATTI mode.

This is the third or so mavic with compass interference I've seen on here go missing in the last week!

Be mindful of your takeoff location. It's important to ensure there are no magnetic metal objects near the Mavic when taking off.

 

[sar104]

@onelobos, here's a link to your uploaded flight log:
DJI Flight Log Viewer - PhantomHelp.com

At the end of your flight log, your Mavic was drifting with the wind close to this red line:

View attachment 28240


Assuming the remote controller disconnected from the Mavic close to the end of the flight log, it would have drifted for about 23 more seconds before it was able to descend low enough to land (or make impact with a tree/building).

Start looking for it in this yellow box:

View attachment 28239

If the OP immediately shut down the RC that may have happened, but he did not give any indication that he did so and it had a full strength connection up to the point that the app stopped. So that's certainly a minimum estimate of how far it may have gone, although you have indicated it drifting of the order of 1000 m in 23 seconds. It was moving at around 5 m/s at the end of the flight, so I think you may have a factor of 10 error in there - that should probably be nearer 100 m. If you project a 3 m/s descent path with that assumption you get the following - I didn't bother to post it earlier because without firm information on the duration of the RC connection it's somewhat baseless:

 

[msinger]

I think you may have a factor of 10 error in there

Yep. I updated my image above.

 

[sar104]

Yep. I updated my image above.

We really need to know whether he switched off the RC and, if so, approximately when.

 

[msinger]

We really need to know whether he switched off the RC and, if so, approximately when.

That would be helpful. If he doesn't know when the remote controller disconnected, then all he can do is follow that red line (if not found in the boxed off yellow area).

 

[sar104]

That would be helpful. If he doesn't know when the remote controller disconnected, then all he can do is follow that red line (if not found in the boxed off yellow area).

Agreed. That's potentially a lot of ground to cover though. 300 m or so of extra distance for every minute that it remained connected.

 

[onelobos]

Hmmm...Having the phone shut down has nothing to do with the controller keeping a connection with your drone. It is entirely within control of the controller even without a phone or tablet attached. Now then, let's talk about your Return To Home settings prior to the flight? I can't imagine why it would go rogue if the controller was still communicating with the drone.

That's the problem. The controller said it was disconnected from the drone as soon as the phone shut down. Even so, my husband tried bringing it back anyway with the toggles as I ran inside to charge my phone. We calibrated it's GPS correctly before the flight. I haven't turned on my controller since this incident on 12/27/17. If I turn on my controller, will it revert to the settings it had when I last used it? I'm certain we always had the RTH setting on for every flight. Only difference on this flight was that we turned off "beginner mode." Would that have turned off it's RTH setting?

 

[onelobos]

Right. It didn't go crazy. It switched to ATTI mode and started drifting away with the wind since the OP made no attempt to control it (according to the data in the flight log).

Thank you so much @msinger, as well as everyone here who offered advice/analysis/help!!!! Within 6 hours of my original post, DJI sent me an email with a coupon for a new Mavic Pro. Coincidence? I think not.... I will study this forum earnestly before even lifting my new Mavic Pro off the ground. This forum is invaluable!!!!!

 

[Bensjamming]

It works great when the Mavic is not flying in ATTI mode.


Be mindful of your takeoff location. It's important to ensure there are no magnetic metal objects near the Mavic when taking off.

How close does something like that have to be for it to affect it? Like say taking off 15 feet from a parked vehicle ok or should one walk a ways away if possible?

 

[JROD]

So is it worth attaching a separate GPS tracker of some sort so we can find our MP's? Anyone invest in one?

 

[sar104]

That's the problem. The controller said it was disconnected from the drone as soon as the phone shut down. Even so, my husband tried bringing it back anyway with the toggles as I ran inside to charge my phone. We calibrated it's GPS correctly before the flight. I haven't turned on my controller since this incident on 12/27/17. If I turn on my controller, will it revert to the settings it had when I last used it? I'm certain we always had the RTH setting on for every flight. Only difference on this flight was that we turned off "beginner mode." Would that have turned off it's RTH setting?

If the controller really did disconnect at the same time (although there is no apparent reason for that to have happened), then it should have descended as shown in post #22. The trees shown there, or the rest of the box area that @msinger showed in post #14 are worth checking.

 

[dbyantis]

So is it worth attaching a separate GPS tracker of some sort so we can find our MP's? Anyone invest in one?

Marco Polo is a tracker that has been mentioned, you need to be aware of some others that require cell towers and a subscription, if there is no cell coverage where you fly they won't help. If the MP is managed properly, there really is no need, in my opinion.

 

[JROD]

Marco Polo is a tracker that has been mentioned, you need to be aware of some others that require cell towers and a subscription, if there is no cell coverage where you fly they won't help. If the MP is managed properly, there really is no need, in my opinion.

My heart still races a bit every time I look up and realize how high it is. Hope that feeling never goes away LOL.

 

[Dan]

this fly away is crazy and it's amazing how fast dji offered a replacement. congrats,

 

[kakao]

this fly away is crazy and it's amazing how fast dji offered a replacement. congrats,

It was most likely obvious to them that there was no pilot error thus the gesture.

 

[msinger]

How close does something like that have to be for it to affect it? Like say taking off 15 feet from a parked vehicle ok or should one walk a ways away if possible?

It depends on the size of the metal object. I doubt anything 15+ feet away would affect the compass. In most cases, the object is within a few feet of the compass.

 

[dvarapala]

How close does something like that have to be for it to affect it? Like say taking off 15 feet from a parked vehicle ok or should one walk a ways away if possible?

In my experience moving the MP as little as 2-3 feet is enough to make the error messages go away.

 

[radman]

I have been practicing landing on the 8 foot square deck of my boat while it is parked on land in front of my house. When the Mavic is within about 6 feet of the deck, I receive numerous error messages about the Mavic automatically switching between the front and back compass. I’m certain the errors are caused by strong permanent magnets in the bilge pumps just below the deck. I can successfully land on the deck, but I must move the Mavic to a new location about 8 feet away before I can take off again.

 

[viam]

Appreciated your detailed analysis of this Mavic loss incident on 12/27/17 3:34PM EST. Can you pls share the specific software tool(s) you used to analyze the data? Thank you.

 

[Endeavor]

I have two major crashed under my belt so far and both were user error. Also both were during litchi missions. With my P3 & P4 it was common to loose connection however the quad would complete the mission as planned and I would regain video at some point when it came back into range. The times I crashed were due to incorrect settings on one waypoint were the quad descended into the ground or light pole in my case. I could have prevented both accident by simply ending the mission and allowing the quad(s) to pause where I would then regroup and manually rise and rth. In both cases I froze and in both case I learned how to replace all sort of parts. I now pre-plan for unexpected occurrences and keep myself prepared for emergency's and have a escape plan in place if I need it. I think in the OPs case I would have done the atti to gps move to freeze the quad then a RTH where once in visual range one could regain control and land. This is how we learn, some of us the harder way.