Mavic disconnected, and flew away.

[Mee]

Hello,

I've already post in the DJI forum, but they told me to come here.
So what happened, is that I was flying for about 5 minutes, the Mavic was flying perfectly, but at some point, the DJI Go 4 (Nexus 6) disconnected, but reconnected right after, and disconnected again, it did that 7 or 8 times in a row. Then the controller disconnected from the drone.
At this point, the drone was at about 10 meters high, and there was nothing between the controller and the drone, as I was almost underneath the drone. The Mavic started to fly up, and away. I disconnected my Nexus 6 from the controller, and started to run after the drone, I regained control without any explanation, and flew it back in my garden, and landed safely.
Over at the DJI forum, they said that I've lost connection, and the Mavic started to go home, but to a Home Point that was not where the Mavic took off. But I'm sure that the Mavic recorded the home point when it took off, the phone told me that : "The Home Point has been updated".
Moreover, in the flight log in the DJI Go App, the home point seems behind the house, somewhere I had never flown before. What do you think ?
So I'm worried to fly again, does my mavic has any issues ? Or it was just in a bad mood, and I'm safe to fly again being more careful ? Or it was all my fault ?

Here is the post at DJI Forums : Mavic flying away
Here are the .txt flight logs : Phantom Log Viewer - PhantomHelp.com - Phantom Log Viewer - PhantomHelp.com
Here are the healthy drone flight logs : HealthyDrones.com - Innovative flight data analysis that matters - HealthyDrones.com - Innovative flight data analysis that matters

Thanks for your help,
Mee

 

[james_mav]

Was your takeoff point on top of a building?

 

[Mee]

No, not at all, it was at the bottom of the house, in the garden.

 

[Strafe1]

I've seen on previous threads that your home point can be recorded incorrectly if gps is poor or interference is present. Consider following the protocol for uploading your flight .dat file for expert review on this forum.

 

[DodgeP]

A couple of things kind of bother me about your story. 1) after you lost control, gained control multiple times when you lost it and it flew away and chased it, gained control again, you didn't land immediately???? You flew it back to where you took off? 2) Your home point was listed somewhere you had never flown? Cool, how about the home point was in a place where you turned the mavic on and initially recorded a home point and this time you never really got the message you're stating about home point recorded; just shoot up 10 meters and took off to flying.

Pinpoint the issue; try the DJI Go4 app on a different device. ( I think most stable device is an IOS ). When was the last compass calibration performed? What was the KP index at the time of your flight? I was just telling someone the other day about how I wasn't as thorough with my pre-flight checks as I should be and the 1 time I did crash it was because of me - as much as I wanted to blame the device, it was the operator.

 

[BD0G]

We can armchair quarterback this one all day long, but that is merely conjecture and best guesses.

If you want to know specifically what happened upload your flight log to this thread and then let some of the pro's here delve into what actually happened.

If you want to know , do the work to upload it here.

We cannot pat you on the back and say everything is great with the Mavic Pro you own if there is no solid data to analyze.

 

[Mee]

Here are the flight logs from the Mavic. The first one, a window opened when I launched the Assistant, and I copied the files : Flight Logs - Google Drive
The second one, I saved it from the Assistant, by doing the data upload thing, which resulted in one file : Flight Logs Assistant - Google Drive

 

[BD0G]

In the first set of files which flight number is the one in question? There are a bunch listed.

 

[MavicPro]

When it told you home point recorded please check it on the map. Did you check it on the map? Did you confirm that the home point that was recorded was accurate?
I ask because I was flying my P4P in Big Bear, launching from the shore next to the lake, when home point was recorded in checked it on the map and for some reason the home point was saying I was in the middle of the lake. I moved a few feet down the shore, restarted everything and this time home point recorded was accurate.

Sent from my SAMSUNG-SM-G935A using MavicPilots mobile app

 

[SYC12]

When it told you home point recorded please check it on the map. Did you check it on the map? Did you confirm that the home point that was recorded was accurate?
I ask because I was flying my P4P in Big Bear, launching from the shore next to the lake, when home point was recorded in checked it on the map and for some reason the home point was saying I was in the middle of the lake. I moved a few feet down the shore, restarted everything and this time home point recorded was accurate.

Sent from my SAMSUNG-SM-G935A using MavicPilots mobile app

Good point about checking HP on the map. I'll put it on my per-flight list.

 

[cluc]

I never take off unless I get the notification Home Point has been recorded, please check on map.

• Even after that, as soon as I take off, I'll manually tap to record the home point once more.

 

[Tas47]

On the 'lost signal' issue it's important to keep the RC antennas aligned so that the flat faces are facing the quad. With the Mavic almost directly overhead the antennas should have been laying flat not pointed towards the quad.
I'm not sure if that was the cause, but it's a common mistake.

 

[Blucenturion]

Great tip.

 

[Cyberpower678]

The flight logs are useless in this case, because the RC was disconnected. I see the home point was set correctly, you were also in beginner mode. I see no indication of a RTH in progress in the log. I see a class D airspace warning in there and the drone may have tried to leave the airspace and land outside of it. I can't say anything concrete with these logs, and that I would need to see the black box data itself to offer up anything in this case. @msinger is even better however at reading flight logs than I am. Maybe he can offer up something.

 

[msinger]

The TXT flight logs don't show much. I can see the home point was not set to the correct location -- or the current location was not being reported correctly. You can tell something odd occurred there since the home distance was 71.6 feet away when the home point was set.

I'd suggest you try flying again in a wide open location that has no nearby obstacles. That'll at least give you enough space to properly test everything out.

 

[SYC12]

Mee,
Don't know if you know GO4 app has your flight logs all saved and can be "play" similar to video with map in the background. All your RC stick movements, MP flight path, warning messages and etc will be shown in real time. Have you looked into this yet?

 

[Mee]

In the first set of files which flight number is the one in question? There are a bunch listed.

I flew only once on the 24th and had the problem after few minutes. All the files are dated from this date, that's why I assumed they were all relevant for you. Is there is a way for me do distinguish the valid ones ?

 

[tcope]

It appears to me that when you set the home point you only had 7 sats. While this is "doable", it's very low for what you should be getting. Seems like not enough time may have been given to establish a good GPS position.

 

[BudWalker]

I looked at this flight some. I should know better but I'm gonna guess that the Mavic was turned on inside the house close to the recorded HomePoint and then carried through the house to the launch point. Maybe the inside location was close to a window allowing enough GPS reception?

The first HomePoint was recorded at -90.157
-90.157 : 458968642 : 4881 [L-HOME]First. lati:48.8035022 longti: 2.1407743 alti:126.09
This coincided with gpsHealth increasing to 4.

After that the accelerometers and gyros look like the Mavic was carried some.


During that interval the GPS coords show the change in location

The green circle is the start location (with the yellow A) and the green circle is the launch point.

Normally, the Mavic will update the HomePoint during launch. I think that it just got confused because of the unusual sequence of events. The gpsHealth had increased to 4 which normally coincides with the Go App giving the green ready to go indication. But then it dropped on the trip through the house. If the Mavic were smarter maybe it would re-started the launch sequence.

 

[JAY DEE]

I never take off unless I get the notification Home Point has been recorded, please check on map.

• Even after that, as soon as I take off, I'll manually tap to record the home point once more.

How do you manually tap to record home point? Thanks in advance!

Sent from my SM-T280 using MavicPilots mobile app