I was flying yesterday evening over a river and at about 1400 feet away from me and Altitude of about 250 feet clear line of sight. with no warning I lost total signal to drone and it just hovered. It did not initiate RTH. I waited about 2-3 minutes nothing so I started running towards the drone and I was able to get signal back. All setting in DJI GO was correct with RTH if lost signal. I would be happy to upload any files you need to see. I'm a new pilot so just let me know what you need and how to get them to you. Thanks for your help


Ron Allison




http://healthydrones.com/main?share=TxtnZt

The most likely explanation is that you just lost the video downlink which commonly drops out before the contril signal is lost.
If so you would have still had full control of your Phantom and it would have been hovering waiting for you to do something.
You could have activated RTH.
You can tell if you still have control signal if the LED on the controller is green.  It becomes red if you lose control signal and the Phantom will initiate RTH itself 3 seconds after control signal is lost.

DJI Go said disconnected. I added the report from healthy drone if that helps

ronall50 Posted at 2016-8-9 09:23
DJI Go said disconnected. I added the report from healthy drone if that helps

If you click on the Notifications tab, HD confirms what I guessed:
Downlink data connection lost ( Data Loss ) means that the remote got partial or no flight data from the aircraft for more than 1 second, which means the data downlink had issues.

It is possible that during this time there is a sense of full control of the aircraft via the remote as well as clear video, however typically the video gets choppy and the remote controls may have some delay.

This is typically an indication that the aircraft was flying in a high interference area or that distance was a negative factor. In these conditions the aircraft is at higher risk of initiating the Return-To-Home function.

I just looked at your data, if I read it right you were flying @ 260 feet up, and return to home altitude is set @ 196 feet, it may have looked like it was hovering, buitwhen signal is lost it goes to alititude set hieght first, then starts to head home

Heebus Posted at 2016-8-9 09:50
I just looked at your data, if I read it right you were flying @ 260 feet up, and return to home alt ...

If it was flying at 260 ft and RTH is set for 196 ft, when RTH is initiated (and it wasn't on this flight) the Phantom would just come home because it is already higher than RTH height.

I had the same experience flying over water; I went from 100% signal strength, to DISCONNECTED!

I still do not know the reason, but my speculation was:

I was flying in custom single channel mode.  There is a higher risk of losing video if you fly using a custom (single channel frequency) connection, than if the P4 was hopping between different channels.


But it was not just the video lost, I (and it seems you too) also lost the uplink connection at the same time.  My connection loss lasted more than a minute and I also started walking towards the P4.   I thought initially I may have been jammed, as I was flying by a lighthouse.

I see a bridge by you; do they have any security systems there?  In NY they do and thus they should be avoided.

labroides@yahoo Posted at 2016-8-8 20:00
If it was flying at 260 ft and RTH is set for 196 ft, when RTH is initiated (and it wasn't on this  ...

my bad, wasnt sure if it would lower to hieght or not, guess I shouldnt have chimed in... sorry all

Thanks everyone for all the help! This was the first time happening to me and I freaked out being new to this. I never even hit the RTH button but for some reason I was thinking once I lost signal it won't do anything.

ronall50 Posted at 2016-8-9 11:15
Thanks everyone for all the help! This was the first time happening to me and I freaked out being ne ...

The trouble is, under the programming that DJI writes, 'Disconnected' means that the signal back to the RC unit from the aircraft has been lost. It would avoid putting the frighteners on new pilots if the wording was changed to something more meaningful and not as scary, like 'Downlink from Aircraft Lost'. The important thing to realise is that you have NOT necessarily lost control of your aircraft at this point.

Word of caution. If you are a new pilot don't fly over rivers - until and unless you 100% have to and want to take footage from or of that water.
In other words, don't fly recreationally (constantly) over places where you cannot easily retrieve your drone if it goes down.

This is even more important if you buy DJI care or 3rd party insurance since you need to return the drone if it crashes...losses are almost never covered.

Once you 100% understand the technology - then you can make decisions which involve risk better - that is, are you willing to take the risks for the rewards?

Geebax Posted at 2016-8-8 22:06
The trouble is, under the programming that DJI writes, 'Disconnected' means that the signal back to ...

Doesn't Disconnected with the red light on the RC also mean that the uplink is gone too?

I thought when the red led is on, RC inputs will not reach the P4.

droneflyers.com Posted at 2016-8-9 12:17
Word of caution. If you are a new pilot don't fly over rivers - until and unless you 100% have to an ...

Very good advice. My other favourite piece of advice is never to upgrade antything after you just took it out of the box.

MD_Icarus Posted at 2016-8-9 13:29
Doesn't Disconnected with the red light on the RC also mean that the uplink is gone too?

I though ...

Actually, the RC unit has no way of knowing if the uplink to the aircraft has been lost.

No, it means the RC unit is not getting anything back from the aircraft, and the warning is badly worded. In most cases, after you see that message, you can still control the drone. the easiest way to find out is to simply tilt the gimbal using the S1 switch, that will tell you if the aircraft is still receiving.

Geebax Posted at 2016-8-8 23:49
Actually, the RC unit has no way of knowing if the uplink to the aircraft has been lost.

No, it m ...

If that is the case, then there should be 2 warnings:
1- if the connection from the P4 to the RC is lost (as you state, same as the current one )
Plus
2 - RC is not communicating with the P4.

This way, we will know that the RC can still control the P4.

So all we have to do then is put it in Home Lock and Bring it back.

I know I am singing to the choir, but I hope DJI also considers allowing Home Lock in Sports Mode.  This will allow us to bring it home at the most efficient speed.

But then again, the P4 will go into RTH automatically when the connection is lost though, unless we fly an autonomous flight.

______________________________
Thinking out Loud here:

Since RTH is initiaited by the firmware, that tells me that there must either be a "handshake" signal control between the P4 and the RC (i.e. when the P4 is sending data to the RC, it expects a reply), or the P4 is expecting a signal every few seconds.  If it does not get any after the pre-determined time limit, it activates RTH.  But if the RC uplink is working, then it will not cause RTH to initiate? Is the RC telling the P4 it is disconnected to initiate RTH?

The more I think about the details, the more confusing it gets!

MD_Icarus Posted at 2016-8-9 22:57
If that is the case, then there should be 2 warnings:
1- if the connection from the P4 to the RC is ...

'Since RTH is initiaited by the firmware, that tells me that there must either be a "handshake" signal control between the P4 and the RC (i.e. when the P4 is sending data to the RC, it expects a reply), or the P4 is expecting a signal every few seconds.  If it does not get any after the pre-determined time limit, it activates RTH.  But if the RC uplink is working, then it will not cause RTH to initiate? Is the RC telling the P4 it is disconnected to initiate RTH? '

RTH is iniated by the aircraft, it is only done from the RC when you press the button. There is no handshake between the aircraft and the RC, but the aircraft does expect a periodic signal to be sent from the RC unit. It is the absence of this signal that triggers a lost signal in the aircraft. But that 'lost signal' is completely different and separate to the one from the RC unit. The RC does not report loss of signal to the aircraft, as it is not crucial to the operation of the system. The return video feed is considered non-essential.


'Is the RC telling the P4 it is disconnected to initiate RTH?'

No.

labroides@yahoo Posted at 2016-8-9 07:19
The most likely explanation is that you just lost the video downlink which commonly drops out before ...

Hi guys. I have my bird p4 and fly 700meters when i start to get image transmission weak signal. But still have strong remote signal. Then after 850meters. I got a ni signal. Screen froze and remote led is turns to red. Still bird didnt initiate the rth. Why? I try pressing the rth button on the remote but got no luck. I  walk a little then i see it turns green. Then i press the rth button and it went back home to me. Why my " no signal and remotes led turns red" didnt initiate my rth?

When my p3s initiate rth fast once i got a no signal warning. Please help

The situation was I had it comming back to me in P mode. It was about half way back working correctly.  It was about 150 or 200 yards away and up about 150 feet.  Suddenly I lost signal. I could still see the drone but it would not respond. Controller said weak signal. There was actually none. I kept trying to get it to come back. but couldn't send any signal.  Video transmission was also lost. It wouldn't return on its own. I could see the paper airplane on the andriod screen pointing at a spot probably near it resting spot, maybe. After searching still no sign of it.

No GPS location on screen of bird or transmitter on P4. Happened to me before with my H502s. Both positions were on the tx and I walked to it in a couple of minutes.

I contacted DJI. We checked the flight data. I don't really know how to read it but it's on the DJI GO app.
I have no vid, it's on the P4 sd. Is ther some way I can use the flight data to help locate it. I didn't see and GPS co-ordinates.

Any help welcomed, of course.

In any event Happy Holidays!
       Bill

Could KP Factor have any affects on RC Signals like it does with GPS Signal?? I'm starting to think Solar Activity Maybe playing a bigger roll then i had thought in my problem and some other different problems i have been reading about. Which might be part of my Video downlink from my lightbridge connection problems that i have been experiencing since 1.8 RC update? . I Hear about Large metal structures, and power lines, and radio/cell-phone antennas/towers, WiFi, causing Problems which i'm not to much around when flying farm land. Could KP be a Major factor in all of this? And if so could Update 1.8 be over sensitive to such interference and not show up in the HD settings as interference on the channels?  

lK89jQGlZCVm Posted at 2016-12-13 04:38
The situation was I had it comming back to me in P mode. It was about half way back working correctly.  It was about 150 or 200 yards away and up about 150 feet.  Suddenly I lost signal. I could still see the drone but it would not respond. Controller said weak signal. There was actually none. I kept trying to get it to come back. but couldn't send any signal.  Video transmission was also lost. It wouldn't return on its own. I could see the paper airplane on the andriod screen pointing at a spot probably near it resting spot, maybe. After searching still no sign of it.

No GPS location on screen of bird or transmitter on P4. Happened to me before with my H502s. Both positions were on the tx and I walked to it in a couple of minutes.

Have a look at the flight record in DJI Go. When you first open it up (the screen where you select aircraft) you'll see a paper plane top left hand corner of screen. Tap on that and it should bring up a list of flights. Tap on the latest one and that should give you a playback of that flight, beside the controls at bottom edge of screen you should see GPS co-ordinates. Also the editor in DJI Go may hold the last video returned (assuming you were caching video on your display device).