Phantom 4 Lost in River

Tom Fournier · Jul 11, 2017

Hey everyone. First ever post.

I bought a used Phantom 4 Black Edition on eBay. I installed the Argtek Range Extender in the controller. I had one good flight, I had it over 2600m away. On my second flight, about 200 ft out, it suddenly dropped like a rock into the Kennebecasis River where it remains. I took a newbie look at the flight data but it didn't give me any clues as to what happened. Thought you guys might be able to shed some light on what happened... Cheers Tom

UpLift Aerial · Jul 11, 2017

Upload your flight log here.

It's the log from the go app I think. I haven't done it before but I'll get @msinger to explain it.

tevek · Jul 11, 2017

Use this link and follow the instructions:
https://www.phantomhelp.com/LogViewer/Upload/

UpLift Aerial · Jul 11, 2017

tevek said:
Use this link and follow the instructions:
https://www.phantomhelp.com/LogViewer/Upload/

That's what I thought. Thanks for clarifying! [emoji108][emoji106]

UpLift Aerial · Jul 11, 2017

You can also upload the same file here too.

UpLift Aerial · Jul 11, 2017

Here's the log:
DJI Flight Log Viewer - PhantomHelp.com [incorrect log]

Notice near the end you get a ton of speed errors and compass errors. RTH (return to home) was set to 30m. See in on the map look like you took off from the dock correct? And landed in what must be your backyard? If it landed. Seems to have on the map but you say it "fell like a rock". Hmm...

Meta4 · Jul 11, 2017

UpLift Ariel said:
Notice near the end you get a ton of speed errors and compass errors. RTH (return to home) was set to 30m. See in on the map look like you took off from the dock correct? And landed in what must be your backyard? If it landed. Seems to have on the map but you say it "fell like a rock". Hmm...

The Phantom was launched frm a point about 24 feet above the river.
When it was coming back things started to go wrong at 5:03.3 and the Phantom started spinning and tumbling as it fell.
The speed error messages and the first of the compass error messages are caused by this.
It hit the water at about 5:04.6 and all data after that is invalid.

I can't see that it's related but the throttle is reading backwards in the data.
It looks like the drone would climb when the throttle was pulled back.

Tom Fournier · Jul 11, 2017

Wow this is all very interesting

And I do like my controls custom set so that pulling back on the left stick raises the drone...

Meta4 · Jul 11, 2017

Tom Fournier said:
And I do like my controls custom set so that pulling back on the left stick raises the drone...

Well that explains that little mystery.
But the Phantom seemed to be responding properly to the controls and there's nothing in the control inputs to explain the crash.

tevek · Jul 12, 2017

In addition to what Meta4 has offered up, is it possible you had a bird strike at the relatively low altitude you were flying at? The speed dropped from 8 mph to 0 mph and then it was all over.

UpLift Aerial · Jul 12, 2017

I uploaded the flight to airdata (healthydrones) as well.
Airdata UAV - Flight Data Analysis for Drones [incorrect log]

UpLift Aerial · Jul 12, 2017

Wait, wait wait. Hold on a sec. Tom, look at the map on the logs and see if that is where you were flying when it crashed because the log on airdata says it's a p3s.

UpLift Aerial · Jul 12, 2017

Yea, we've got the wrong log. Take a look at the date of flight.

Tom Fournier · Jul 12, 2017

Video of incident in question

UpLift Aerial · Jul 12, 2017

I believe this to be the right one [emoji4]

Airdata.com (healthydrones): Airdata UAV - Flight Data Analysis for Drones

PhantomHelp.com: DJI Flight Log Viewer - PhantomHelp.com

UpLift Aerial · Jul 12, 2017

Noticed you started with 37 on battery. That is never a good idea. Many crashes have been caused by beginning a flight with battery that is not fully charged.

UpLift Aerial · Jul 12, 2017

Tom Fournier said:
Video of incident in question

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I'm very curious as to why it's so shaky and cutting out and lost connection so fast. One thing to always remember is to turn of VPS (vision positioning system) when flying over water. The VPS can confuse the aircraft when over water.

Tom Fournier · Jul 12, 2017

Apologies to everyone for the confusion. I initially submitted my P3S logs in error (that drone crashed also, but there was no question that was my fault)

UpLift Aerial · Jul 12, 2017

Tom Fournier said:
Apologies to everyone for the confusion. I initially submitted my P3S logs in error (that drone crashed also, but there was no question that was my fault)

Was not your fault. It no one's fault.