Hi I'm pretty new to drones. We are on vacation at the moment and this morning I had an odd thing happen with the drone. It just descended out of the sky and went into landing mode? Not at the home point it was around 8 meters or so from it.. luckily in reach for me to grab it prior to landing in the ocean.  The flight log shows 11+ GPS says and no message regarding signal loss. Why would this occur? And more how can you regain control of the drone?  I had around 8 mins of flight time left?

A little more information about the incident would be helpful, to hopefully get to the bottom of this. What was the battery level? Were you using return to home? were there any notifications about the behaviour in the app?

The battery according to the flight log was around 84% at the time it started to descend from 94m, the landing comment displayed around 40 meters. And nope I wasn't doing anything just taking pics at the time or video. No commands are visible in the flight log on screen. And presumably seeing as it recorded the whole thing on the phone signal had not been lost either?

You may have unwittingly pressed RTH. You can turn off the RTH by pressing the red X on the screen.

That's the thing during return to home there is a red X visible on screen, bit in this instance that wasn't the case? Nor did a return to home prompt get logged in the app.  I had no control of the drone at all most odd? As I say luckily I was able to get hold of it and flip it upside down which stopped it. When I get home I will certainly be sending the log to dji to get more info. Just hope the drone makes the trip with me..

You say you were flying over water, was the sun on it, there is a section in the manual about flying over reflective surfaces, can cause issues with the 3D sensing and vision systems

I was yes.. 94m high mind you.. so I'm doubtful the sensors would affect it at that height.  That excerpt also says if no GPS signal and at the time I had 11 sats...

JazUK Posted at 2017-11-24 03:57
I was yes.. 94m high mind you.. so I'm doubtful the sensors would affect it at that height.  That excerpt also says if no GPS signal and at the time I had 11 sats...

You may upload your flight record to this link and share it with us: http://www.phantomhelp.com/LogViewer/Upload/
You'll find the file in the DJI folder of your mobile device in the subfolder \flightrecords.
With that we'll probably be able to tell you more about what has triggered the bahaviour of your Spark.

Hi watchberger..

Thanks for that. I have uploaded the log.. interesting.. at the point of descent it says forced landing.. 18sats and no comment on the side?

Lol finally uploaded the log outside the dji app lol here's the link to the log..
http://phantomhelp.com/logviewer/HTSKEM06D4LADBKWY19O/

JazUK Posted at 2017-11-24 04:29
Lol finally uploaded the log outside the dji app lol here's the link to the log..
http://phantomhelp.com/logviewer/HTSKEM06D4LADBKWY19O/

This is an interesting one. Have there been clouds or mist where you have been flying? If you look at the VPS altitude column you will see that your visual positioning system quite a number of times and especially when the "forced landing" started believed to be close to the ground. Nevertheless this would not explain the Spark's behaviour because when caught in a cloud it would rather hover and refuse to go anywhere.
I hope somebody more experienced than me can provide the explanation.

JazUK Posted at 2017-11-24 03:57
I was yes.. 94m high mind you.. so I'm doubtful the sensors would affect it at that height.  That excerpt also says if no GPS signal and at the time I had 11 sats...

Just to verify, did you check that your drone have good GPS signal before flight? Please ensure that no interference around your drone. If it is not caused by environment, you can export the flight data and the black box and provide to us for further check.

Wachtberger Posted at 2017-11-24 04:47
This is an interesting one. Have there been clouds or mist where you have been flying? If you look at the VPS altitude column you will see that your visual positioning system quite a number of times and especially when the "forced landing" started believed to be close to the ground. Nevertheless this would not explain the Spark's behaviour because when caught in a cloud it would rather hover an refuse to go anywhere.
I hope somebody more experienced than me can provide the explanation.

I'm still thinking the reflection's off the water have caused this, similar to the cloud and fog threads previously.

jksphoto Posted at 2017-11-24 04:50
I'm still thinking the reflection's off the water have caused this, similar to the cloud and fog threads previously.

Yes, can well be...

Hi all.. actually virtually no clouds in the sky at the time.. we are in the Seychelles it's very sunny.

It's odd if it's the water as when I flew over the water a few mins earlier (different flight and battery) there were no issues. And it was literally at the shores edge.. so waves passing in and out.. I'd post the video if the internet here were better.

Hi dji Electra,

Yes very good gps signal.. 11+ sats upto 18 at the time.

I will look into posting the info you have asked for. Hopefully it can be done via the mobile app as I'm on vacation and won't return home to a pc until the 6th.

Hi dji Electra,

Yes very good gps signal.. 11+ sats upto 18 at the time.

I will look into posting the info you have asked for. Hopefully it can be done via the mobile app as I'm on vacation and won't return home to a pc until the 6th.

Ah.. just watched the video.. I won't be able to do that until after the 6th. Will the data still be in the drone at that point? I'm still intending to fly it whilst on vacation.. that's what I brought the drone for..

The SPARK is loosing communication link with the RC ....The current version 0.7000 has a software issue on the SPARK firmware...This has been experimented by me and found to be true...Also downgrading the firmware to 0.6000 will not solve the issue either ))  You have to use NLD software to correct the communication link issue until DJI rectifies the software....Be careful at high altitudes...

JazUK Posted at 2017-11-24 06:23
Hi all.. actually virtually no clouds in the sky at the time.. we are in the Seychelles it's very sunny.

It's odd if it's the water as when I flew over the water a few mins earlier (different flight and battery) there were no issues. And it was literally at the shores edge.. so waves passing in and out.. I'd post the video if the internet here were better.

how was the position of the sun?
I think, watchberger pointed in the right direction.
You were descending.
Maybe reflections told the visual system, you are almost down, 3 feet, 1.6 feet, 1 feet
but you still "confirmed  landing" with the trying to get it down.
So it was in landing mode, even with visual in greater distance as 1 feet or such.

Have you ever tried, to ascend?
Or to fly it a little bit?
Or switched into sport?

Anyway, the first question is the one: Did you try to ascend?
If you dont know, check joystich moves in the flight log "video"

Wachtberger Posted at 2017-11-24 04:47
This is an interesting one. Have there been clouds or mist where you have been flying? If you look at the VPS altitude column you will see that your visual positioning system quite a number of times and especially when the "forced landing" started believed to be close to the ground. Nevertheless this would not explain the Spark's behaviour because when caught in a cloud it would rather hover and refuse to go anywhere.
I hope somebody more experienced than me can provide the explanation.

I think you are right!
The VPS 'saw' it near the ground, reflections maybe.
Pilot still wanted it to go down, critical distance (1 feet), confirmed landing this way
And after it tried to land as it got told to.

S-e-ven
The sun was pretty much overhead as it was approaching mid day. And I wasn't actually descending, the drone did and I couldn't do anything about it.  And yes of course I've had the drone flying around. In fact only 5 mins previous to the forced landing I'd just completed another flight on a full battery which went fine.

Hi subu,
Although in my log you can see a couple of Comms drop outs I don't believe this to be my issue. Loss of Comms to my understanding will invoke a return to home and this was not that. The drone simply went down in the exact spot it was at, at the time.. luckily for me this was in reach this time!!

JazUK Posted at 2017-11-24 09:44
Hi subu,
Although in my log you can see a couple of Comms drop outs I don't believe this to be my issue. Loss of Comms to my understanding will invoke a return to home and this was not that. The drone simply went down in the exact spot it was at, at the time.. luckily for me this was in reach this time!!

Now I have had a bit more time to look at it and my answer concerning your connection losses is yes and no. Overall they were too short to initiate RTH, but they started right at take off time and later reappeared again and again. This clearly indicates interference from somewhere and seeing the location, the interference might have come from your mobile device or another device around. Was your mobile device in airplane mode or or had it mobile network or bluetooth switched on? Or were you wearing a smart watch? Or was another person with such devices near you?

S-e-ven Posted at 2017-11-24 08:57
how was the position of the sun?
I think, watchberger pointed in the right direction.
You were descending.

I mentioned the sun first

jksphoto Posted at 2017-11-24 12:33
I mentioned the sun first

It is not a contest

JazUK Posted at 2017-11-24 09:41
S-e-ven
The sun was pretty much overhead as it was approaching mid day. And I wasn't actually descending, the drone did and I couldn't do anything about it.  And yes of course I've had the drone flying around. In fact only 5 mins previous to the forced landing I'd just completed another flight on a full battery which went fine.

So you did not descend from 300 feet down, to the moment, when "Forced Landing" started?
That is important.
Sun 'over the  Spark' is this close to shore a big chance of 'reflections in the eyes of the spark'
Because if you did, you may have accidentely 'forced the landing' by trying to descend, when the spark thought 'opsi, only one feet to the ground'
And it doesnt matter for this case, if you could fly it 5 minutes before.
it is important, what you tried or could/could not do, when it started landing in 130 feet height:
Did you try to ascend? switch to sport? Fly it more towards you?
That what I mean with 'watch the flight record and the stick moves'

I mean, you wanna fly it in the next days.
Because it was already in confirmed landing mode, it would have landed on or better in the water, methinks

You may check this topic
https://forum.dji.com/forum.php? ... p;page=1#pid1047312
and watch the last minutes of the video
To see my point of asking how much control you had or tried at the landing point

Hi guys,
Thanks for all the help and feedback.

Yes looking back through the video I was indeed descending slowly so the stick on the remote was down up until at least the point of forced landing. After the forced landing no more movements are registered so I guess i couldnt have  done any as I was moving to go get the drone. So is it better to have to vps off? I thought I read somewhere it's best to leave them on for stability, but if the result is random landings mid flight the better off turned off lol

JazUK Posted at 2017-11-24 21:24
Hi guys,
Thanks for all the help and feedback.

It's two different things. There is the "obstacle avoidance" that you can switch on and off. And there is the "visual positioning system" (VPS) that you cannot control. You'll find the details about both on page 11 onwards in the user manual.

Ah.. so I'll have to keep close watch on it then.. I presume in evidence of failure of this kind dji would sort out a replacement? That's assuming it can be proven to be something not working correctly.. which I'd have to assume would have been the case in my instance?  I've not got the manual with me, but if it can't be turned off and isn't working quite right it seems to be more a hindrance than help? In most of my flight where the vps height is zero the drone was above land.. I've not had much confidence to take it over water much at present being a new drone owner.  My caution looks to be right deserved! Are dji working on these kinds of faults? Maybe an algorithm or warning the vps and gps differ by too wide a margin? Giving us a chance to take action rather than grin and hope for the best.  Certainly during my forced landing no Stop/pause buttons were available just hope if it happens again I can take control via the sticks..  

JazUK Posted at 2017-11-25 03:33
Ah.. so I'll have to keep close watch on it then.. I presume in evidence of failure of this kind dji would sort out a replacement? That's assuming it can be proven to be something not working correctly.. which I'd have to assume would have been the case in my instance?  I've not got the manual with me, but if it can't be turned off and isn't working quite right it seems to be more a hindrance than help? In most of my flight where the vps height is zero the drone was above land.. I've not had much confidence to take it over water much at present being a new drone owner.  My caution looks to be right deserved! Are dji working on these kinds of faults? Maybe an algorithm or warning the vps and gps differ by too wide a margin? Giving us a chance to take action rather than grin and hope for the best.  Certainly during my forced landing no Stop/pause buttons were available just hope if it happens again I can take control via the sticks..

I actually have to admit I did assume only, that the 'forced landing' will give you the same options, as the 'critical battery landing' gives you.
For my understanding, only the reason is different but only DJI knows!

I kind of was hoping, that you had a little movement in the flight record.
Still during forced landing already happened.
Your saying you had nothing leaves again two options:
Either you did not try for 100+ feet, ....?
Or the Spark blocked every input.
Would be interesting to know.

The topics with fog/cloud flights and auto landing are different from the case:
They had no visual. At least before the battery was empty. ;-)
But the one and the other mentioned, that they could fly it horizontally.

(And I had tried that, instead, better before jumping to the shoreline)

Yes.. to be honest t happened pretty quick.. there were no options to cancel of that I'm sure.. the flight log didn't register any movement from the point of forced landing.. I'm pretty sure I'd have tried to bring the drone to me away from the water as it was only 8m away and easily visibl, but I can't guarantee without doubt that to be the case.. only assume so will have to wait and see.. but yes it is a little worrying.. I will certainly follow it up with dji. Does anyone know how long the black box data is held for as I can't download it until I'm back home in around 19 days time.

JazUK Posted at 2017-11-25 05:54
Yes.. to be honest t happened pretty quick.. there were no options to cancel of that I'm sure.. the flight log didn't register any movement from the point of forced landing.. I'm pretty sure I'd have tried to bring the drone to me away from the water as it was only 8m away and easily visibl, but I can't guarantee without doubt that to be the case.. only assume so will have to wait and see.. but yes it is a little worrying.. I will certainly follow it up with dji. Does anyone know how long the black box data is held for as I can't download it until I'm back home in around 19 days time.

No, there is usually no 'cancel' option, when 'forcing' the spark to land via stick. Because this is usually after the autostop in 30cm / 1feet over ground.
the cancel option is only showing up, in case you are  using the 'now landing' function from the display.
Which is a 'are you sure' slide confirmation,methinks
Because you can start (force) that landing from a real flight height.
And, of course, you can hit that button by accident.
(Never landed that way from high altitude, but I remember accidentely hitting the button and the slider 'landing now, are you sure' or something like that, showed up.
With said 'cancel' option