[size=14.6667px]I decided to fly my spark today over an open field trying to see how far I can go with it before it loses signal and come home.. So on a fresh battery I let it flew thinking if it doesnt come home on its own.. I will hit RTH when battery hits 60% trying to be safe.

[size=14.6667px]About 2000 ft in.. I lost signal .. and sure enough it turned around and started coming home.
[size=14.6667px]But then it never came home... I ended up spending the next hour.. in a field looking for it.
[size=14.6667px]With the last know coordinates.. I eventually found it.

[size=14.6667px]If there is a DJI support person monitoring this thread..
[size=14.6667px]I would love to know why my bird lost altitude and crashed.

[size=14.6667px]I am attaching a video...
[size=14.6667px]At about 1:00 min mark I lost signal.. and the bird turned around and started its climb to RTH altitude of 60m.
[size=14.6667px]Then at about 1:23 it begins its flight home. Then about 1:40 it rapidly lost altitude and eventually crashed.
[size=14.6667px]No bird strike.. no nothing.. Just gradually went down.

[size=14.6667px]Why ?

[size=14.6667px]Here is the youtube clip of what happened.

[size=14.6667px]https://www.youtube.com/watch?v=Bo8uP74gTME

[size=14.6667px]Here is the flght log

[size=14.6667px]http://www.phantomhelp.com/logviewer/0DO0X7WMVPIQVWGCHM54/

I decided to fly my spark today over an open field trying to see how far I can go with it before it loses signal and come home.. So on a fresh battery I let it flew thinking if it doesnt come home on its own.. I will hit RTH when battery hits 60% trying to be safe.

About 2000 ft in.. I lost signal .. and sure enough it turned around and started coming home.
But then it never came home... I ended up spending the next hour.. in a field looking for it.
With the last know coordinates.. I eventually found it.

If there is a DJI support person monitoring this thread..
I would love to know why my bird lost altitude and crashed.

I am attaching a video...
At about 1:00 min mark I lost signal.. and the bird turned around and started its climb to RTH altitude of 60m.
Then at about 1:23 it begins its flight home. Then about 1:40 it rapidly lost altitude and eventually crashed.
No bird strike.. no nothing.. Just gradually went down.

Why ?

Here is the youtube clip of what happened.
https://youtu.be/Bo8uP74gTME

Here is the flight log
http://www.phantomhelp.com/logviewer/0DO0X7WMVPIQVWGCHM54/

I lost my drone in a tree how do I locate it

Hmmm, that is interesting.  I'm glad to hear you found your Spark.  I had a quick look at your logs and video and I don't see anything obvious for why it lost altitude during the RTH.  I would suggest you open a case with the DJI support team (https://www.dji.com/support) and provide them with all the logs from both your phone as well as from the aircraft itself.  If you don't get a reasonable response, then I'm sure one of the DJI mods would be able to assist you.

I’m assuming you weren’t low on battery during the RTH ?

IF you RTH at 60%, i wouldn’t think so, but need to check the obvious first

You didn’t hit the land button did you ?

Very strange indeed and clearly a case for DJI to look at.

fans08dfa64f Posted at 2018-1-16 17:14
I lost my drone in a tree how do I locate it

1.open a own topic
2. use the "find my drone" function

Sir, sorry for your lost. Please contact the Support to start a case, I would recommend you provide the flight records to them and locate the problem. Here is the link: http://www.dji.com/support. Any question, please inform us.   

djiuser_UVPq80r Posted at 2018-1-16 16:47
I decided to fly my spark today over an open field trying to see how far I can go with it before it loses signal and come home.. So on a fresh battery I let it flew thinking if it doesnt come home on its own.. I will hit RTH when battery hits 60% trying to be safe.

About 2000 ft in.. I lost signal .. and sure enough it turned around and started coming home.

Doesn’t show what might have caused aircraft to lose altitude, I did notice that in RTH mode your rudder is being pulled back right up until end of log, could it be a problem with RC stick calibration, would be worth checking out.

Cookster670 Posted at 2018-1-16 23:02
I’m assuming you weren’t low on battery during the RTH ?

IF you RTH at 60%, i wouldn’t think so, but need to check the obvious first

No... Battery was at 78%   See flight log.

DJI Elektra Posted at 2018-1-19 03:59
Sir, sorry for your lost. Please contact the Support to start a case, I would recommend you provide the flight records to them and locate the problem. Here is the link: http://www.dji.com/support. Any question, please inform us.

I posted this to the DJI forum. So far noone from dJI contacted me.

hallmark007 Posted at 2018-1-19 04:24
Doesn’t show what might have caused aircraft to lose altitude, I did notice that in RTH mode your rudder is being pulled back right up until end of log, could it be a problem with RC stick calibration, would be worth checking out.

How do you determine that ?
All the RC numbers at the last record in the CSV .. are the same as at the point when the RC signal was lost. All 1024 except the rudder which was 1018.  Rudder controls the yaw of the aircraft .. not elevation.. which could simply mean the aircraft may have tried to adjust heading during RTH.

What is puzzling to me is .. why the last known altitude is at  55.1 ft. ??
Almost look like the aircraft once disconnected.. stopped registering the flight log.
But the RTH behavior should still return to HOME or Hover .. not descend rapidly as clearly seen in the youtube video.  

Still have not been contacted by anybody at DJI to explain this mystery.

Thank you for contacting DJI Support.

Here was the last email I got.
Your request (942083) has been received and is being reviewed by our technical support representatives. We will contact you soon. (Business hour: Monday to Friday, from 07:00 am to 15:00 pm PST)

Best Regards,
DJI Support

Never exceed 400 ft mate unless you meant horizontal distance from the 2000ft

djiuser_UVPq80r Posted at 2018-1-19 05:03
How do you determine that ?
All the RC numbers at the last record in the CSV .. are the same as at the point when the RC signal was lost. All 1024 except the rudder which was 1018.  Rudder controls the yaw of the aircraft .. not elevation.. which could simply mean the aircraft may have tried to adjust heading during RTH.

In RTH all values should stay at 1024 they should record any change unless controller is moving sticks. So my assumption was either your remote was stuck on 1018 rudder or you were pushing stick , so could there be something wrong with remote needing calibration.
If you say that it wasn’t you pushing on stick then it shouldn’t be reading anything else in RTH except 1024.

djiuser_UVPq80r Posted at 2018-1-19 04:56
I posted this to the DJI forum. So far noone from dJI contacted me.

I would recommend you enter the website and start a case: http://www.dji.com/support. You can provide me the case number so I can track the case status for you.