Help needed with drone mystery!

SparkDroneCSI · Jul 11, 2018

Hello folks! I was hoping I could borrow your expertise to help solve a little problem. Here's my sad story.

I was flying my drone, getting some footage as one does, when I lost connection. The drone began a RTH (I was out of sight range), clipped a tree, tumbled, falls, and then just...disappears. It appears dead. No connectivity whatsoever.

I've attached the flight log.

Looking at the flight log, there are three possibilities:
1. It fell to the ground. The ground has been extensively searched.
2. It is stuck in a tree. Entirely possible, although the last data point shows the drone still falling. There are several possible trees and they are TALL, it's possible the drone is stuck up there and we just don't see it yet.
3. Dunked in the lake. This theory is strengthened by two things. 1. I'm pretty sure the GPS is a little bit off (connectivity is poor in this area, and I've attached an illustration) Compensating for the difference puts the final data point right over the lake. 2. The drone shut off completely right after that point. That makes me think water?

So I guess the key question is: does a drone spontaneously shut off when it has a sufficiently hard collision with a tree? Is the spontaneous shutting off a suggestion of a water landing? What does the "Not Enough Force ESC error" message mean?

Any help you guys can provide a newb would be much, much appreciated. Thanks!

Haggi · Jul 12, 2018

I would try in the DJI forum if not already done.
Some really great guys over there!
Sorry about your loss.

Koala Tails · Jul 12, 2018

If a spark is flipped over it shuts down immediately, (It prevents a power dive into the ground). A small branch can easily flick a spark upside down, your phone/ tablet will record an error. I don’t remember if it matches the error you described.

Chippy147 · Jul 12, 2018

I'm not sure of that actual error message, but ESC's are Electronic Speed Controllers and control the speed (!) of each motor. If your Spark did hit a tree, anything preventing a motor spinning (branches etc) may cause the ESC error and cause the ESC to shut down the motor. It doesn't explain the loss of signal though.

Ran van · Jul 12, 2018

Koala Tails said:
If a spark is flipped over it shuts down immediately, (It prevents a power dive into the ground). A small branch can easily flick a spark upside down, your phone/ tablet will record an error. I don’t remember if it matches the error you described.

I agree with you.

Fireman Sam · Jul 12, 2018

Could be some one /something has picked it up..........

SparkDroneCSI · Jul 12, 2018

Koala Tails said:
If a spark is flipped over it shuts down immediately, (It prevents a power dive into the ground). A small branch can easily flick a spark upside down, your phone/ tablet will record an error. I don’t remember if it matches the error you described.

So in this case, (as other folks have mentioned) we wouldn't expect the drone to shut itself off COMPLETELY. It would in theory, continue to transmit. So is the total loss of power suggestive of a water landing? I would think that when a drone hits the water, it would continue to broadcast for a second or two before everything gets flooded, but the recording just stops while the drone is still at least 30 feet in the air.

Haggi · Jul 12, 2018

The spontaneous shut off power when hitting something, could very likely be the battery popping out.

SparkDroneCSI · Jul 12, 2018

Haggi said:
The spontaneous shut off power when hitting something, could very likely be the battery popping out.

That seems very likely. So collision with tree, battery pops out, then nothing.

landude · Jul 13, 2018

You can view you flight log here DJI Flight Log Viewer - PhantomHelp.com
It looks pretty good, your sat count was a little low in the beginning, did you set the home point?
It start returning home you can see that in the log. Then about 1000 feet out there were gps errors. Are you sure it clipped a tree? If you look at the map it looks it looks like the flight ended at the beginning of the tree line.
There was still 42% battery so if it didn't go down it could have flown off anywhere with those gps position no match errors.
Also I noticed you were enjoying sport mode and the bird was out 3,032 feet, where at that point it lost connection with the remote and started it's own RTH. It looks like you got control back around 4m 5s. Not sure about the errors at the end but you almost had it. Least that what it looks like to me.

landude · Jul 13, 2018

After looking at this with Google Earth it may have went down. unzip this, then open with Google Earth and maybe the terrain will look familiar to you.

SparkDroneCSI · Jul 18, 2018

Hey folks! Thanks a bunch for your insight!

So, I went out to the "crash area" two days later, and found the drone in the weeds under the tree where it had crashed. The drone clipped the top of a tree, must have gotten stuck in one of the lower branches, then blown down. Fortunately there was no rain over those few days, so it seems to be in fine working order. It hard enough that the battery was actually knocked out, which explains why it was powered off.

Here is the crash, in case that's interesting to anybody:
SparkCrash720.mov

Thanks again!

landude · Jul 18, 2018

Good to hear, what damage was done to the bird?

Rafa7 · Jul 19, 2018

SparkDroneCSI said:
Hey folks! Thanks a bunch for your insight!

So, I went out to the "crash area" two days later, and found the drone in the weeds under the tree where it had crashed. The drone clipped the top of a tree, must have gotten stuck in one of the lower branches, then blown down. Fortunately there was no rain over those few days, so it seems to be in fine working order. It hard enough that the battery was actually knocked out, which explains why it was powered off.

Here is the crash, in case that's interesting to anybody:
SparkCrash720.mov

Thanks again!