And so it happened. Biggest worry came true. Took the spark out this afternoon to catch the last few rays of the sun and do a fly around of a local tower. Moved the spark to about 80m high and just over 60m away from my start point. Got my angles right and initiated the active track mode. Home point was recorded on start point so all looked good to go. I set my active track to begin a fly around and when I looked up to the drone it started to move. But in an away direction. I looked back at the screen to see what was going on but it was just showing the tower zooming away as it flew off. I then had lost signal and disconnected. The image remained frozen on my screen. As a last ditch I hit return to home and waited for its return, this didn't happen and with time running out I was in a panic. Drone was out of site and not coming home. I went into the find my drone option and went to where it was last recorded and to my dismay could not find any sign of it. I also looked back on the flight log and see a new home point was set just as it was going into active track. It again set a couple more as it flew away. The speed also shot up as if it was in sport mode which I had off due to me going into active track. I'm gutted, just got it a few months ago and now it is gone. Though it is just a low range model it is by no means something I can readily afford to loose.

During active track it kept flying away rather than around the subject and then at some point it lost the subject after about 350m travelled. It continued on to about 530m and all through the flight log it shows between 15 to 18 satallites connected so at no time did it loose the connection it would seem. What threw me off was the new home points it was adding as it flew away. My return to home as a last ditch and a subsequent wait was the stressfull bit. When it didn't show it was a race to find it with the battery dying slowly as I tried to get there in time. I can only hope it is where I think it might be but this was in a nursery and they were locked up at the time. Possibly hit a tree on RTH. But I set RTH at 50m. And I am sure that this was lower than where I started so what happens then? Does the drone descend 50 m and wait for me to initialize the landing or does it decend all the way to the ground using the sensors before auto landing?

I have sent a mail to DJI support and hope that some resolution can come of this, if not I will be gutted to loose my little spark.

Hi. I am sorry to know what happened to your DJI Spark. I understand that you already sent an email to DJI Support regarding this issue. Just in case please create an online repair request as well. I will post the online repair request link for reference ( www.dji.com/support ). Please sync the flight record of your DJI Spark as well using the DJI Go 4 application.

>> and do a fly around of a local tower...

What kind of tower? Page 46 of the Spark User Manual:
"Minimize interference by avoiding areas with high levels of electrmagnetism, including base stations and radio transmission towers."

Active track can back off a subject but think everything is good.  It is using the subjects positioning and changing size to hold position.  You need to apply forward stick pressure to stop it backing up.  Once it loses its radio link with the remote controller, it will RTH to the established home point.  It will auto land where it is if it has no GPS lock (no way of finding home point) and no radio link.

Interesting that your Spark started spewing new home points as it flew off.  Like the home point was set to update instead of stay at the launch location and it had a valid radio link to the remote controller.  People walking trails or traveling across a lake on a boat like to set their Spark to constantly update the home position.  But it will land at the last update (with GPS-P mode) if it loses radio link to the pilot.

marlowe Posted at 2018-7-1 12:34
>> and do a fly around of a local tower...

What kind of tower? Page 46 of the Spark User Manual:

Radio tower. But have never had an issue around it before. Except for birds spooked as I flew past and they attacked the drone. I also took the drone away from the tower this time to a range of around 70-75 m away from the tower before I began the active track. I have done active tracks before around the same tower but a lot closer. This time I wanted to do a long arc around and not so close for the very reason not to be close to it for interference. I have flown a lot in this proximity with no issues at all. It is a wide open field from the tower all the way up past my house and beyond and I mainly fly in this open area with no problems.

Wazat Posted at 2018-7-1 13:12
Radio tower. But have never had an issue around it before. Except for birds spooked as I flew past and they attacked the drone. I also took the drone away from the tower this time to a range of around 70-75 m away from the tower before I began the active track. I have done active tracks before around the same tower but a lot closer. This time I wanted to do a long arc around and not so close for the very reason not to be close to it for interference. I have flown a lot in this proximity with no issues at all. It is a wide open field from the tower all the way up past my house and beyond and I mainly fly in this open area with no problems.

>> Radio tower. But have never had an issue around it before. Except for birds spooked as I flew past and they attacked the drone. I also took the drone away from the tower this time to a range of around 70-75 m away...

75m is way too close. The tower may transmit differently at different times. Maybe you were lucky before.

I hope DJI will help you out, but I would call this pilot error.

Update - Drone recovered. All seems ok. Clipped a tree perhaps on landing. No apparent damage slight ding on one prop but not broken. Find my drone works ok but paired it with a dedicated GPS  unit which led me right to the right spot. A little search and eventually located it in amongst plants. Unfortunately no video footage of the crash only that of the flyaway until it lost connection it seems.

Wazat Posted at 2018-7-1 23:11
Update - Drone recovered. All seems ok. Clipped a tree perhaps on landing. No apparent damage slight ding on one prop but not broken. Find my drone works ok but paired it with a dedicated GPS  unit which led me right to the right spot. A little search and eventually located it in amongst plants. Unfortunately no video footage of the crash only that of the flyaway until it lost connection it seems.

Great to hear you were successful recovering it. I hope the flight log can shed some light on what happened.

Glad you found it! Could you say a bit more about how you recovered it? What do you mean by pairing find my drone with a dedicated GPS unit?

Interesting, it sounds like it could have been electromagnetic interference - but glad you found it, how did you actually track it down then?

Wazat Posted at 2018-7-1 23:11
Update - Drone recovered. All seems ok. Clipped a tree perhaps on landing. No apparent damage slight ding on one prop but not broken. Find my drone works ok but paired it with a dedicated GPS  unit which led me right to the right spot. A little search and eventually located it in amongst plants. Unfortunately no video footage of the crash only that of the flyaway until it lost connection it seems.

Well done ! Happy you found it Wazat !

sorry to read that

by the way welcome to the forum

I would be interested to see your log to see if there is anything we can learn from it.  Can you try uploading the log from your phone/table to the following site and paste the resulting URL here for use to try to learn from your experience?

http://www.phantomhelp.com/LogViewer/Upload/

In regards to your comment about it updating the home point, it sounds like you had enabled the Dynamic Home Point feature.  Can you check on that in your settings?

KlooGee Posted at 2018-7-2 04:53
I would be interested to see your log to see if there is anything we can learn from it.  Can you try uploading the log from your phone/table to the following site and paste the resulting URL here for use to try to learn from your experience?

http://www.phantomhelp.com/LogViewer/Upload/

I would not want to discourage analysis - we may learn something, but it should be made clear that when flying in the vicinity of a large radio tower one may encounter extremely high RF interference resulting in failure of any or all of the systems Spark depends on for navigation and control. Is is possibly the worst mistake one can make.

You may get away with it if you are lucky since the electromagetic field can be stronger or weaker at various point around the tower, but really it should be avoided.

marlowe Posted at 2018-7-2 08:40
I would not want to discourage analysis - we may learn something, but it should be made clear that when flying in the vicinity of a large radio tower one may encounter extremely high RF interference resulting in failure of any or all of the systems Spark depends on for navigation and control. Is is possibly the worst mistake one can make.

You may get away with it if you are lucky since the electromagetic field can be stronger or weaker at various point around the tower, but really it should be avoided.

I agree, but that is also what is fun about looking at logs and learning is that you can explore the area via mapping tools or Google Earth.  You may be right that this flight was impacted by the tower, but maybe there is other info in the logs that shows something different.  Always something to be learned when looking at data.  I've found many times that when looking at the data it sometimes has a different story to be told than what was expected without looking at it.  Cheers!

Glad you recovered it.