Mavic Air disconnect while in RTH

[Flydude]

Hi There,

my brother has had the mavic air for a short time now ( i have actually never seen it - we live in different places) and today he took out his air for a short flight.

He told me, he is usually only flying with the smartphone (without the controller). Today after 2 minutes in flight (always VLOS) the DJI Go4 App told him, that the signal was weak. He immediatly activated RTH.

The drone did gain alot of altitude (much higher than he ever flew - he told me; so i am assuming the drone flew to the standard 30 m height) and then flew into the direction of the home point - when, suddenly the mavic air disconnected from his phone (iPhone 8).

The drone did not complete the RTH but instead stayed right on spot. He told me, that he tried to restart the app, but that did not help - he even mentioned, that usually he has to scan the qr-code to establish the connection (i don't know about that, i fly a mavic pro, with the controller, so i got no idea).

The drone stayed there in the air until the battery was completly drained, it descended a little bit before hitting the ground (snow). the rotors where still slowly turning he told me.

Now the battery won't charge - i presume it has been deeply discharged. The drone itself seems to be without damage, but he has no way to power it up, as he has only one battery.

My questions:

1) i would assume, that the mavic air should have finished the RTH, no matter if the controller (in this case the smartphone) disconnected. Does anyone have a clue how to avoid this in the future?

2) is there a way to retrieve the log from the drone, to see what really happened there?

3) do you think DJI will replace the battery?

Thanks in advance!

 

[msinger]

is there a way to retrieve the log from the drone, to see what really happened there?

You can retrieve the TXT flight log from the mobile device like this or the internal DAT flight log like this.

 

[tcope]

He told me, he is usually only flying with the smartphone (without the controller).

This is really an accident waiting to happen.

1) i would assume, that the mavic air should have finished the RTH, no matter if the controller (in this case the smartphone) disconnected. Does anyone have a clue how to avoid this in the future?

RTH can be set to hover. He would need to connect to the Air and check this setting (it's stored on the drone itself so a connection is needed. Also, if the battery reaches 10%, the drone will then just start to land. So it could have been at low battery (this can be changed but the default is 30%), started to fly back to the home point but then reached 10%.

2) is there a way to retrieve the log from the drone, to see what really happened there?

Yes, it's stored on the display device. You can search the forum on how to do this.

3) do you think DJI will replace the battery?

If it's less than 6 months old. However, it's unusual for it not to charge. When it was plugged into the charger what did the lights do? That is, did they blink? The online manual explains what the blinking lights mean. Is he able to turn the battery on and then put it on the charger?

 

[Flydude]

Here is the flight log from the iPhone: DJI Flight Log Viewer - PhantomHelp.com

Currently he cannot retrieve the log directly from the mavic because he will need some battery power to do that.
The battery seems to be completly dead - so we have to wait.

According to the log the RTH was initiated, but then the connection loss happened. The drone even flew towards the Homepoint. But according to my brother it only hovered after loosing the connection. That seems like a software bug to me.

But we will see - i will update this thread as soon as i get new intel.

Best regards

 

[msinger]

Here's the log without the bogus battery data:
DJI Flight Log Viewer - PhantomHelp.com

Unfortunately, the TXT flight log does not contain anything after the Mavic started ascending prior to returning to the home point. The next step would be to look at the DAT flight log (since data is recorded there even when the Mavic is disconnected from DJI GO).

 

[RoadieMunky]

There is a setting in the go4 app, for lost connection, in there you can set it to do 1 of 3 things. Land, hover or return to home. Tell him to check that setting before he fly's every time and select accordingly. As it sounds like it was set to hover.
Hope this helps.

 

[Flydude]

Quick Status Update:
the retailer (cyberport - germany) is willing to replace the defective battery, but has none in stock (it's pretty hard to get one in germany right now). DJI said, they would replace the battery too, if the retailer will send the defective part to them - which is what my brother did. Still waiting for updates.
In the meanwhile i ordered a new battery as his birthday is near. With luck, it will arrive at the end of march.

Before that, he has no way to power on the mavic air to get to the DAT log.

While i was flying with my mavic pro yesterday a ran into a problem which could have been alot like his:

i was flying around (afternoon, away from the sun) and at about 300 - 400 meters i decided to hit the RTH button. the drone did not come back to, instead it was moving some meters away. The problem was, that the mavic was facing directly into the sun and the collision detectors reacted to that (the do that sometimes and think the sun is an obstacle).


Wouldn't i have a connection i could not have stopped RTH and the drone would probably hover until the battery was drained. I canceled RTH, entered sport mode (to quickly disable the sensors) and returned home. The DAT-Log confirmed this behaviour.

Maybe something like this happened to the mavic air of my brother? He did tell me, that there was no bright sunlight at the day he flew, but maybe something else triggered the obstacle sensors. I don't know if APAS kicks in whe RTH is active on the Mavic Air, but with it, the drone should have taken an alternative route.

 

[Grizzo]

As someone said earlier, it looks like your brother had the setting to 'hover' if you lose connection. If you lose connection, you can set it to hover, land or RTH.

Check the settings next time you turn it on and set it to RTH if that's what you want it to do on signal loss.

 

[Flydude]

Thanks a lot for your responses.

The battery I ordered for my brother did arrive and we could power up the drone again.

It was really set to hover - so yes, the drone did do what it was supposed to.

Never the less it is good to know: if you want to initiate RTH, be sure not to have "hover" activated on signal loss.

My brother immediately changed the setting afterwards

 

[RoadieMunky]

Glad you're all sorted [emoji3]