I lost my Spark over the weekend and I am trying to figure out if there was a malfunction of some sort. The drone appears to have decided to land on its own--midflight and some 540 ft from its home location. I had initiated the auto return to home, but rather than descending above the home location it descended from where it was at that point. The drone appears to have hit a tree and crashed. I did go looking for it at its last known location but could not find it. The last seconds of the video shows it landing on a road but it was not there by the time I got there. I suspect someone helped themselves to it.  

  

Flight logs are here: http://www.phantomhelp.com/LogViewer/4JUR1C2DZUNHZ1M4LRBV/

  

I have opened a case with DJI.

  

In the meantime, if anyone can diagnose the issue or has insights on what might have gone wrong, I would greatly appreciate hearing from you.  

  

Thanks

Hi, I must admit that I am not experienced enough to provide you a full explanation of what might have happened in your case. Therefore I can only share initial observations from your flightlog. You have taken off with a battery that was not fully charged. I usually try to avoid this because the overall flighttime of a Spark battery isn't that much even at full charge. On the other side, if you have been aware about your limited available flight time it was not a "no go" by itself I believe. Much more important is your take off location, a parking deck if I see it correctly. This means a building with lots of metal within concrete. And this explains why you had a significant interference at take off time "In Flight, working compass encounters magnetic-field interference". You should have had a warning on the screen of your mobile device as well, is that correct? For me personally, this would have been the point to abort the flight immediately and look for an alternative take off location. Shortly thereafter the voltage information of your battery turns yellow. This is the first time I am seeing this and therefore can not provide any interpretation on whether this indicates an issue or not. The rest of your flight does not show serious error messages and I can not see why your Spark went into Auto Landing at the time it did.
But I am sure that one of the much more experienced pilots in this forum might be able to tell you more. And it is good that you have already started a case with DJI Support to evaluate your flight data. Have you uploaded it for them already?

The log doesn’t show it hitting a tree, in fact the log finishes at 0.3 metre from the ground this is where I would expect it to finish in auto landing.
Auto landing occurs when Aircraft reaches critical battery or when Aircraft doesn’t have enough battery to rth .
At 29% your spark had enough battery to rth , but went into auto landing, so what had you set critical battery at?

As was said above taking off with not fully charged battery can cause problems, just because battery says 50/60 % if this was lying around for a few days it may not contain what readings are saying.
So if you take off with battery at 50% it does not contain the same 50% as the battery you run down from 100% to 50%. This could have caused Aircraft to go to critical and auto land.

Your log doesn’t show rth button pressed also so if you did push the button then I think it was already inauto landing mode so pushing button will have no effect.

Could someone have picked it up from the ground, would it be worth asking in the area if someone might have found it, I think the spark will be in perfect condition. Last known coordinates below.

40.48419718        -74.4348252

Maybe was mistake taken with buttons landing instead RTH ? But serious ... Aircraft not autolanding without reason, even 'compass errors' would still fly in ATTI. Mine autolanding once on the tree I'm not flying very close trees anymore.   Why you take off without full battery and flying far then?

Maybe battery indication in orange/yellow means low temperature alert?

Thanks for your responses.

How does one set the critical battery level before it starts to auto land? Seems to me 30% is rather high. I feel that it would have easily reached its home point even with 30% level.

I also did not get any warning or notification that the drone was going to auto land due to low battery. i recall that on an earlier flight that i did get a warning to bring drone home due to critical battery level.  not sure why i did not get one this time.

fans69d65158 Posted at 2017-11-29 14:32
Thanks for your responses.

How does one set the critical battery level before it starts to auto land? Seems to me 30% is rather high. I feel that it would have easily reached its home point even with 30% level.

The reason you didn’t get warning could have been because battery was much lower than the reading it was giving you, this could be caused by battery standing for X amount of days, if this was the case then although you thought there was plenty of battery the likelihood was there was only enough to land.
Your battery readings were 3.5 volt at end of flight I’m not sure what reading should be for 29%.

That’s my best guess, it doesn’t mean there couldn’t be a malfunction but dji will be able to tell you more on this.

hallmark007 Posted at 2017-11-29 14:54
The reason you didn’t get warning could have been because battery was much lower than the reading it was giving you, this could be caused by battery standing for X amount of days, if this was the case then although you thought there was plenty of battery the likelihood was there was only enough to land.
Your battery readings were 3.5 volt at end of flight I’m not sure what reading should be for 29%.

In my understanding, we can not set critical battery but only the level for getting a warning.
There was a 'no control at 10% battery' topic somewhere, and DJI said no changing critical batt level.
If the battery level of a auto discharged battery is not shown right in the app, that is / would be a real issue.
And I remember, I wanted to check on one of my batteries, because the given flighttime on the last flight did not correspond with the shown starting level.
Also, when I came back home, I had that said battery showing me 2 steady lights in charger, instead of one. Which would have given me the 'missing'' minutes air time.
Just bad weather keeping me from doing so and I am not that big of a fan, hovering a battery down indoors.
But still on the 2do list.

Anyone ever had something like this?
A flight of only 7minutes, about, with a 'full' battery?

Sorry about your accident. Please contact our support and start a case first: http://www.dji.com/support. I would recommend you upload your flight data to dropbox and provide it to our support. I believe they will help you locate the problem. If you have any doubt in your case, please contact us. Thanks for you patience.

S-e-ven Posted at 2017-11-29 18:12
In my understanding, we can not set critical battery but only the level for getting a warning.
There was a 'no control at 10% battery' topic somewhere, and DJI said no changing critical batt level.
If the battery level of a auto discharged battery is not shown right in the app, that is / would be a real issue.

There is a problem if you are depending on battery reading particularly when flying with a battery that’s sitting around for a week or so , it may show 60% when starting flight but this will never be the same as the 60% you get when running down a battery from fully charged 100%, there are other ways to see what the actual power is left .

Another problem I see when using the app to rth there is a slide on the app there is also a slide for landing it can be easy to make the mistake to select landing instead of RTH , we see from OP’s log it says nothing about RTH but it does say Landing was initiated and this could well be the case here only the OP can tell us if this could have happened.

hallmark007 Posted at 2017-11-30 02:08
There is a problem if you are depending on battery reading particularly when flying with a battery that’s sitting around for a week or so , it may show 60% when starting flight but this will never be the same as the 60% you get when running down a battery from fully charged 100%, there are other ways to see what the actual power is left .

Another problem I see when using the app to rth there is a slide on the app there is also a slide for landing it can be easy to make the mistake to select landing instead of RTH , we see from OP’s log it says nothing about RTH but it does say Landing was initiated and this could well be the case here only the OP can tell us if this could have happened.

I think I see your point.
But they called "intelligent batteries"
So I assume that the app can and has to show the right amount of battery power and the available flight time.
Minimum it should be able, to correct this during the flight.
The LEDs maybe can be wrong, but they are anyway only showing an "about that", probably looking for the voltage.

If it is like with older smartphone batteries, showing 50%, but a sec later shutting down, because they can't "hold it/deliver" anylonger, this would be a totally unsafe setup for a flighing object!
The phone can be connected to a powerbank, or such. But the drone ......

DJI Support came back with the following analysis of the logs:

   1. The aircraft worked in GPS mode and responded to the pilot's command actively;
   2. At t=04:02, h=43 m, d=165.4 m, Landing was trigerred in the APP by the pilot;
   3. At t=04:41, h=1 m, d=165.7 m, the aircraft crashed during landing. The incident point: 40.4841971 -74.4348253.

Now my question is why did the AC land at d=165.4 m rather than returning home and landing at the home point as I had instructed it to?

Also the logs seem to show that aircraft goes from “P-GPS” mode to “Auto Landing” on its own. If the app indeed triggered the landing from current height, how would that have occurred? I don't see a button in the app for it to go into auto landing (except of course via the RTH feature). Might there be a setting that would triggered auto landing? If so which one?


Any thoughts?

fans69d65158 Posted at 2017-11-30 10:22
DJI Support came back with the following analysis of the logs:

   1. The aircraft worked in GPS mode and responded to the pilot's command actively;

It landed there because you selected the land icon instead of the RTH icon.  Small phone so the icons are close together or big fingers that cover the whole left side screen?

Fly it home.  It is just as easy as flying it out.  Reserve the RTH for a backup in emergencies.

fans69d65158 Posted at 2017-11-30 10:22
DJI Support came back with the following analysis of the logs:

   1. The aircraft worked in GPS mode and responded to the pilot's command actively;

Gunship is right I pointed this out in my last post here, you can also see in your log that you did not hit RTH but Landing , it unfortunate you are not the firs to make this mistake, don’t know why dji has set up app this way but that’s the way it is, your much safer hitting RTH button on RC

I am afraid I don't see the land icon in my app, just the rth icon which requires one to slide once pressed.

where is the land only icon?

3 Buttons close to each othter, one for auto landing and one for RTH. (and yes DJI, too close to each other so mistake easily made, imo its needs a ergonomic re-design)

Hmmm I dont seem to see it on my app (iPhone DJI Go v4.1.18)

or does it appear only when connected and flying?

fans69d65158 Posted at 2017-11-30 11:46
Hmmm I dont seem to see it on my app (iPhone DJI Go v4.1.18)

[view_image]

I believe the landing icon will only show when you have the drone in the air. And as you don't on this picture then It shows take off.

Paul Lee Posted at 2017-11-30 11:52
I believe the landing icon will only show when you have the drone in the air. And as you don't on this picture then It shows take off.

Got it.

As Gunship said, this is a design flaw in the app by having the two icons so close together. easy to confuse the two, especially with in bright sunlight

It has also happenened to me already to have pushed the wrong button accidentally, BUT one gets a notification immediately on what is going to happen next and one can correct. I am not trying to defend anyone here, but monitoring the AC and the screen are essential at any moment of the flight. Nobody can take away this responsibility from us. Our Spark is pretty smart, but it does not have AI (yet).