Hi. Yesterday I had an incident with my DJI spark. I started to fly with full battery and with the remote controller. I flew a bit after that I enabled the function "dronie", after completion I began to fly to myself, after few seconds I saw that I lost connection with the drone, but I tried to continue to push sticks to fly to myself and I think it worked but after a few seconds more drone stopped and started autolanding as it happens, when drone has just 10% of battery, but at that moment he had 48% of battery. I ran closer to the shore, hoping that the connection would be restored, but it didn't. Eventually, it landed in a sea and I lost my drone. I'm sure that I didn't do any mistake, but I don't understand why it happened.

I started googling and found the same situation except for the battery level.

Logs: 1 and 2

I have already written to the DJI support and now I'm looking forward to them analyze.

What do you think about my incident? Was it my mistake or it was totally drone mistake?

Hi,

Is it possible that the RTH setting was Hover and not Return Home, if so than when disconnect your drone woould hover and when 10% batt level reached go into autolanding.
There is only 1 record after the first disconnect so hard to tell what happend.

ADD comparison batt VDC yours and random picked file from my Spark ; batt levels are normal.

		cell1	cell2	cell3
at	yours	3,737	3,732	3,705
48%	mine	3,677	3,667	3,663

cheers
JJB

JJBspark Posted at 2018-5-28 10:57
Hi,

Is it possible that the RTH setting was Hover and not Return Home, if so than when disconnect your drone woould hover and when 10% batt level reached go into autolanding.

Unfortunately, I don't remember the setting, but I think I installed to "Return Home". Even if it has been "Hover" he would have had to hover and wait till 10%, but he started autolanding when battery level was 48%. During that flight, I took a few photos and recorded just one video and after that recording happened this accident.

Beniamin Posted at 2018-5-28 11:11
Unfortunately, I don't remember the setting, but I think I installed to "Return Home". Even if it has been "Hover" he would have had to hover and wait till 10%, but he started autolanding when battery level was 48%. During that flight, I took a few photos and recorded just one video and after that recording happened this accident.

ok, better contact DJI support, see what they can find out and do for you.

JJBspark Posted at 2018-5-28 11:20
ok, better contact DJI support, see what they can find out and do for you.

Yes, thanks. I'll be waiting for news from them.

Beniamin, sorry for your loss, that must be frustrating. Since you had contacted our support, please kindly wait for the result, once it is drawn, we will have the proper team to contact you. Thank you for your patience.
If there is anything else we can do, please also reply us, we will do our best to help.

Sorry for your loss mate, the best thing for you to do now is wait for the DJI support answer and provide them with anything they need and ask for.
Best of luck!

Yes, I'm looking forward to the support answer. I created this thread because I wanted to know what people think about the incident and just discuss about it.

JJBspark Posted at 2018-5-28 10:57
Hi,

Is it possible that the RTH setting was Hover and not Return Home, if so than when disconnect your drone woould hover and when 10% batt level reached go into autolanding.

There are different parameters for Return To Tome, depending on how far the Spark is from the home point. I think if it is very close - something like 20 meters - it will just land where it is, and that's it. It's all in the manual, but maybe that's why it landed in the sea?

I didn't quite understand the thing about battery levels: Did it show 10%, when in reality there was still 48% left? Or did it show 48% and you wonder why it went into auto-landing mode? Since you said that you lost connection once, is it possible that you've lost connection a second time? (Sorry, I haven't read your log)

Here's the problem: I think that DJI states somewhere that you shouldn't fly over water. A lot of people fly over water without any problems (if you fly too close to the water, it can confuse the downward sensors, so it's better to keep a few meters of altitude), but usually DJI will use this to refuse any kind of warranty, as far as I know.
EDIT: I've just read your log, not much to see there, no messages at all. It was still in Dronie mode when the log ends, which leads me to believe that maybe, it just did something "funny". I've personally experienced weird behavior when using the Quick Shot modes, so it wouldn't surprise me.

KurtVD Posted at 2018-5-29 07:06
There are different parameters for Return To Tome, depending on how far the Spark is from the home point. I think if it is very close - something like 20 meters - it will just land where it is, and that's it. It's all in the manual, but maybe that's why it landed in the sea?

I didn't quite understand the thing about battery levels: Did it show 10%, when in reality there was still 48% left? Or did it show 48% and you wonder why it went into auto-landing mode? Since you said that you lost connection once, is it possible that you've lost connection a second time? (Sorry, I haven't read your log)

1. I was wondered that the drone started auto-landing because battery level was 48%.
2. In that flight, I lost connection just one time. When I said about lost connection, I meant that I had this experience before.
3. I didn't fly very close to the water, the height was about 8 meters.

JJBspark Posted at 2018-5-28 10:57
Hi,

Is it possible that the RTH setting was Hover and not Return Home, if so than when disconnect your drone woould hover and when 10% batt level reached go into autolanding.

There is a misconception here regarding RTH , you cannot set RTH to home to hover, there are 3 types of RTH and none of them can be set to hover, you can set hover only on lost RC signal, this mode is for very specific situations IE flying indoors flying outdoors undercover or flying from a moving vehicle, when you set to hover your aircraft will hover until low battery which will initiate RTH , if you reconnect before low battery you can fly aircraft as normal.
It also should NEVER be used unless you are always going to have VLOS .

While OP could well have set loss of signal to hover, his aircraft at low battery should have RTH .

Unfortunately your log shows very little you can see it going into dronie mode rising to 27 metres and that’s were the log ends.
If it was in dronie mode, What distance did you have it set at, and it also should have finished this mode by flying back to you and also should have been very close to you, you can see by your log that while flying the dronie mode you were at 48% battery and that was without completion of the dronie. You also say you flew for some time before aircraft started to land, so while you say it was at 48% when landing your log won’t bare that out as it doesn’t add up to what you are saying happened.

There is nothing in your log regarding loss of RC signal .

There is one other noticeable thing in your log, you were flying right on the limit it is safe to fly gps, I just wonder if you lost gps and then RC signal , then procedure for aircraft would have been to land.

hallmark007 Posted at 2018-5-29 14:17
There is a misconception here regarding RTH , you cannot set RTH to home to hover, there are 3 types of RTH and none of them can be set to hover, you can set hover only on lost RC signal, this mode is for very specific situations IE flying indoors flying outdoors undercover or flying from a moving vehicle, when you set to hover your aircraft will hover until low battery which will initiate RTH , if you reconnect before low battery you can fly aircraft as normal.
It also should NEVER be used unless you are always going to have VLOS .

You are absolutely right, i just wrote it 'stupid' down ; i meant the setting when you loose connection wich happened to the OP.
Thanks for correcting me.
Cheers JJB

JJBspark Posted at 2018-5-29 22:18
You are absolutely right, i just wrote it 'stupid' down ; i meant the setting when you loose connection wich happened to the OP.
Thanks for correcting me.
Cheers JJB

No problem, I’ve seen one case this week where operator presumed his drone would hover when it reached low battery, only it flew straight up and hit some trees.

hallmark007 Posted at 2018-5-29 14:36
Unfortunately your log shows very little you can see it going into dronie mode rising to 27 metres and that’s were the log ends.
If it was in dronie mode, What distance did you have it set at, and it also should have finished this mode by flying back to you and also should have been very close to you, you can see by your log that while flying the dronie mode you were at 48% battery and that was without completion of the dronie. You also say you flew for some time before aircraft started to land, so while you say it was at 48% when landing your log won’t bare that out as it doesn’t add up to what you are saying happened.

The drone was coming back after dronie mode when the connection was lost and he started auto-landing. It so strange that logs don't contain anything about lost connection. I don't understand why the connection was lost if I was in the open area, near weren't any metal constructions and I saw the drone.

The only time my AC/RC have lost their connection was in a wide open area, with no obstructions between the two and seemingly no interference but again it was over water (although probably about 30m above the river). Its pretty scary! Fortunately my Spark initiated a standard RTH and it reconnected when it was closer to the RC.

I've learned from experience that you can't always rely on telemetry information being reported from the Spark to Remote Controller. Depending on the situation, especially in the event of disconnects then I've seen battery percentage stagnate until the Spark has reestablished good connection. I don't know why sometimes upon disconnect telemetry properly displays N/A for battery while sometimes the battery accuracy is wrong. The most valuable lesson I learned is never trust telemetry over your own time management skills. If you've flown for longer than the telemetry being displayed such as battery level and time remaining, then it's always a good rule of thumb to disregard remaining battery power indicated from telemetry. There is possibility your Spark disconnected and along the way remaining battery power froze where you misinterpreted the level, although as others stated about your RTH settings I'm not aware you can set Spark to hover instead of RTH?  

Hi everybody. The support has finished the data analysis.

For your case, we have finished the data analysis, and the result is as follows:

1. The aircraft was piloted under GPS mode after it took off, and responded to the pilot's control well;
2. T=07:27, H=2.5 m, D=5.1 m, the pilot switched the aircraft into the QuickShot(Dronie) mode;
3. T=07:38, H=8.5 m, D=30.2 m, the flight record ended and the last recorded coordinate: 44.5479629 34.3434136.

The record ended without any sign of abnormality, so we could not verify what happened afterwards.

We truly appreciate your support for DJI. If you could not recover the product and would like to purchase a new one, we can offer you a 30% off discount for a  Spark Aircraft (without the remote controller and battery charger).

It's quite expected because logs don't exist any information about lost connection and auto-landing

But I have one more question. Why the record ended when the drone was 30 feet away from me and at an altitude of 8.5 meters? How is it possible? How can they explain it to me? Also the last recorded coordinate it's a place over the sea.

no log due to connection lost.

spookster Posted at 2018-5-31 02:21
no log due to connection lost.

So I don't have to prove that the connection lost, do I? Because only in this case the drone could stop record logs.

Sorry for your loss mate, hope DJI can find a solution with you.  keep us posted

Beniamin Posted at 2018-5-31 02:25
So I don't have to prove that the connection lost, do I? Because only in this case the drone could stop record logs.

This is hard to prove anyhow.
You could just turn off/unplug your phone midflight, land the spark safely and try to get another one.
DJI will not replace your spark I guess, probably they will offer you a discount for a new one.
Without providing the aircraft to them I see no chance for any other outcome.

There is a confusion here was the display indicating 10% batter level or 48% battery level.  This will be the main point for analysis and will reveal whether it was a pilot error or a drone malfunction.

I've received the answer from the support again. But unfortunately, they insist that it wasn't a hardware or a software problem, because logs are clear They offer only 30% a discount. It's so sad.

Ask them to tell you what happened then ;)

JimboHUN Posted at 2018-6-2 08:44
Ask them to tell you what happened then ;)

The last message from them was:

Dear Beniamin,

Thanks for getting back to us.

We are sorry for the frustrating experience you have had with our product. We also want to figure out that cause of the incident, however it was not recorded. As you can see the flight record ended at flight time 07'38'', there was no more flight record after that.

There are many possibilities which will lead to the interruption of the flight record. For example, if there was obstacles or interference blocking the remote signal, disconnection may happen; the record also will be interrupted if your mobile device and the remote controller got disconnected; or it also has something to do with the mobile device itself, etc. But all of these doesn’t indicate the aircraft itself malfunctioned. However due to the interruption of the record, the cause for this incident was not recorded, but it can be verified from the record that there was no malfunction found before the record was cut off.

The aircraft was under your control and responded well, it worked as normal before flight record ended. It's not able to locate the main reason according to the flight records you provided, and there are no any error prompts on the app either. The aircraft showed no signs of a manufacturing defect or malfunction during the whole the flight. There are many possible reasons which will cause such a disconnection of the remote signal, although we also want to make it clear and offer you detailed explanation, but we fail to do so with only the flight record available.
If the incident is caused by the pilot's error, we could offer the customer some good suggestion; if it is caused by any product issue, we will try our best to improve our product. Right now we can not rule out any possible speculation. As such, we provide the 30% discount for this case, based on the data analysis result while obeying our policy.

We greatly appreciate your support for DJI. Please consider if you need the offer and get back to us in a month if you need it.

Please feel free to reply us if there is any other questions.

Thanks again for your patience. Have a nice day.

I've written them again, so I'll post the answer later.

Beniamin Posted at 2018-6-2 08:49
The last message from them was:

So they're basically saying they have no way of telling what happened. It may be your fault, it  may be the AC's fault. On a certain level it's understandable. Anyone could fake a flyaway by turning off their phone in mid flight and bringing the AC down by RC only (it's just a hypothetical, if anyone is inclined to test this, be my guest). On the other hand, your loss might be a genuine software error and you would certainly merit a 100%, not a measly 30%.
They keep saying there's no way for them to permanently (or momentarily) turn off the flight capability of a certain AC (like in case it gets stolen or something) so knowing this people might be inclined to fake  a flyaway, in order to profit off a naive DJI support team. But again, I, and I'm certain other folk too, would feel uncomfortable with a third party remote control capability of my AC.
Tough luck man.

Sorry to hear this. How upsetting.

I’m starting to think it’s always a good idea to be recording your devices screen (screen capture) when flying. This provides them With even more information. I did this and also sent the flight data and had better end results than you have so far. Although my Spark did behave differently.

Just an idea for all of us.