Hello everyone, this is my very first post on the Phantom Forum. (Video Proof link down below!)

I've recently purchased a shiny new Phantom 4 and I'm incredibly excited and satisfied about it. I've been using it for about 4 days and has been working flawlessly ever since.
I was keen to try out all of those "autonomous" or "semi-autonomous" features which, as you may know, are unique to the Phantom 4.

Earlier today, after days of perfect flights, both manual and automatic, I've actually found a little issue within its safety ecosystem.

I was hanging with a dear friend of mine in this beautiful park near a river in Northern Italy that makes a great place to use the Phantom 4. I've used it there for the last three days when we also tested ActiveTrack a couple of times already but nothing wrong happened.

Here's the thing:
We did some manual flying and everything was perfect.

Then we decided to retry ActiveTrack out once more, just for the sake of it.
We were using an iPhone 6.
After I selected my friend as a target on the DJI GO app on the iPhone 6, as you may know, a green rectangle appeared around him and he started moving forward.
The drone initiated the following sequence as always, but after a bit my friend took a sharp left, while still being in the frame of the camera and still being tracked and a phone call appeared on the phone.
The Phantom 4 stopped following him, in fact it didn't turn left as it was supposed to. Instead it kept going ahead, towards a tree which was in the nearby. It crushed.
Luckily, no major damages. Just a broken propeller.
Apparently, the two front sensors stopped working, too.
It's almost sure it was the phone call that caused this.
Since it's a new device, it's obvious that things like this may happen but can get fixed via firmware updates maybe, to both the DJI GO App and the Phantom 4 itself.
I didn't find anything about this in the included manuals and istructions that come in the box.One possible quick solution to this would be putting the iPhone into "Flight Mode" so disabling all of its radio signals and prevent phone calls. But it's not a really reliable solution as, you would have to remember to do so before taking off.
The Phantom 4 was luckily still recording so I've also got video proof of it to make everything appear even clearer to you!

(It's up on MediaFire since the forum doesn't allow large files to be attached)
http://www.mediafire.com/download/nsyp2nxr199974k/ActiveTrack_Fail.mp4

If you have comments or opinions about it, feel free to share them.
I made this for general user's awareness and I hope DJI will soon make something about it, as it could get very dangerous.

Maybe we should turn on airplane mode when using our phantoms

medicdanderson Posted at 2016-3-27 20:23
Maybe we should turn on airplane mode when using our phantoms

Yes! Apparently that's the only solution.
Have you watched the attached video?

viktor8@hotmail Posted at 2016-3-27 13:24
Yes! Apparently that's the only solution.
Have you watched the attached video?

Yes! It looked as though you saw what was about to happen and could no nothing about it except come to a slow halt.. And then I'm sure your heart absolutely sank lol. At least it was minor damage!

medicdanderson Posted at 2016-3-27 20:27
Yes! It looked as though you saw what was about to happen and could no nothing about it except com ...

Exactly, luckily it wasn't anything bad, my P4 is still doing great. In fact all of the commands (sticks on the remote) were unusable and the sensors stopped working and the P4 kept going forward since it lost the target it was following. I thought everyone had to know about this, that's why I decided to make a thread about it ;)

This means active track and tap fly are managed by the app and only the app.
If the app goes to background (phone call for example) the tracking stops.

Ulysse Posted at 2016-3-27 21:23
This means active track and tap fly are managed by the app and only the app.
If the app goes to bac ...

That's exactly the point I was trying to make so for everyone to be aware of it. It probably applies to any Intelligent Mode, including TapFly and ActiveTrack.
Sadly DJI didn't mention this in the manual included.

There is nothing magical as DJI may tend to claim it : this is only color analysis (and may be shape) made on the tablet/phone.

If it was still in active track did you try the pause button? That should have put it into a hover

ghtracey Posted at 2016-3-27 16:15
If it was still in active track did you try the pause button? That should have put it into a hover

Yeah, I had the same thought -- the pause button is on the physical RC so you would think it would work even if the app goes in the background.

Yea, put your device on airplane mode/do not disturb mode always! This was clearly specified by DJI on many threads and elsewhere.

Better to put your phone into 'do not disturb' rather than airplane mode, as when it airplane mode you will not receive any map information.

Geebax Posted at 2016-3-28 01:08
Better to put your phone into 'do not disturb' rather than airplane mode, as when it airplane mode y ...

I've tried what you suggested and if you use "Do Not Disturb" on the iPhone, you'll still receive calls, so the app will still get interrupted, since this mode only prevents the iPhone from emitting sounds or vibrating but calls will still pass through. As for map data, even if you activate the "Flight Mode", you'll still get them since the GPS inside the iPhone will still be working even if you turn all other signals like Cellular and Wi-Fi off.

I had a feeling bugs like that were going to appear.  Glad your bird is OK.

viktor8@hotmail Posted at 2016-3-29 04:31
I've tried what you suggested and if you use "Do Not Disturb" on the iPhone, you'll still receive c ...

'As for map data, even if you activate the "Flight Mode", you'll still get them since the GPS inside the iPhone will still be working even if you turn all other signals like Cellular and Wi-Fi off.'

Map data is not received from the GPS signal, it is normal cellular data received from your phone company. The GPS is a completely separate system.

Geebax Posted at 2016-3-28 23:55
'As for map data, even if you activate the "Flight Mode", you'll still get them since the GPS insid ...

Didn't know that. Btw map data is not really important to me, and since there's no other solution to this, we have to renounce to something. I've tried it and "Do Not Disturb" still doesn't solve the problem as phone calls will come through. The app must not be interrupted by something else and go in background, that's what caused the issue in the first place. I hope DJI will make something about it.

microcyb Posted at 2016-3-28 19:36
I had a feeling bugs like that were going to appear.  Glad your bird is OK.

Thanks! Yeah, this kind of bugs are likely to happen, especially with a new product. I hope DJI will sort things out with upcoming firmware updates.

Definitely good to know. I always put my P3P in airplane mode but haven't on my P4. Glad your Phantom is okay!

Wonder if ActiveTrack will work if you initiate a conference video call while flying?

boxerman Posted at 2016-3-29 21:11
Wonder if ActiveTrack will work if you initiate a conference video call while flying?

Is that sarcasm?

Jbundy63 Posted at 2016-3-29 20:24
Definitely good to know. I always put my P3P in airplane mode but haven't on my P4. Glad your Phanto ...

Thanks! I'm happy to have informed you about this possible issue ;)