Mavic lost help- lost RC signal

[d2fino]

Hi friends

It is with great sadness that i've lost my Mavic last week. I have been too sad/depressed everytime i think about it so I have not posted this earlier but i hope you can offer some advice.

I was flying on a good day, not windy on full battery. The day before I had updated the DJI Go app on my iphone6 and there was a new firmware upgrade for the Mavic but decided not to upgrade the Mavic just yet as I had read about some issues.

Before taking off i was asked to do the drone calibration but it asked me to do it again as there was some metal interference, I was a little close to some metal fence so i walked further away like 30metres and did again, then it was fine but it was strange that i was not getting the video feed, it was saying disconnected, I had to restart the mavic and controller at least 2 or 3 times before it finally connected, also i had to do the calibration where you tilt the phone around a circle with a red dot i had to do this a couple of times as well. This seemed very strange because all my previous flights I never had any issues, it always connected straight away and got video instantly never a problem before.

Finally when it all seemed ok then I started take off, there was some trees in front but it didnt seem to be a problem, i started getting some shots but lost line of sight although the drone was only around 250metres away.

Unfortunately I think I got close to a building, suddenly i lost the video feed and connection to the Mavic and got a message that it was doing a RTH, and then I saw another message about motor obstruction and at this point I thought it must have crashed so I quickly went to find it looking on the map I saw the last GPS point was on this building which is a hotel, I went all the way up and searched around the area for a couple of hours but was unable to find it. I think it could have fallen on the pavement also and maybe someone took it I dont know.

Here is my flight log Phantom Log Viewer - PhantomHelp.com maybe someone with experience can tell me something.

I have DJI care refresh but without the drone this will not be helpful. But I want to know if this was a fault with the software, I dont think I should have lost the RC signal, I think maybe when it was close to the building it could have got interference but instead of doing a RTH it seemed to do a TBE and probably crashed against something. Also my RTH altitude was 130metres so enought to clear any buildings or obstacles on the way.

I hope someone can comment and provide some analysis as whether this could be somethign to do with the software, maybe some incompatibility of firmware of the app and the drone.

If this was caused by a malfunction of the device it would be the only way DJI might be able to help me. In the meantime I opened a support ticket and they are analysing my flight record and am awaiting their results.



Thanks a lot for your help
Dan

P.S: its my first drone and only had it for a short time, I may have done some mistakes, we all have at some point, so please dont be too harsh i've learnt my lesson

 

[Cyberpower678]

First off, it's always best to IMMEDIATELY post this as recovering Mavics are as sensitive as investigating kidnappings. You stand the greatest chance of recovering your Mavic within the first 24 hours, and especially with in the first hour of loss.

I'll begin my analysis to see if I can locate it with the flight logs, and determine where the fault is.

 

[Cyberpower678]

To begin, the drone crashed into a hotel, and landed on the lower patio. Someone probably took it by now. Contact the hotel and see if they have anything.

 

[d2fino]

Hi Cyberpower,

Thanks a lot for checking. So number 10 is the last point it should be? When i was there went to the top terrace and tried to look down on patio 9 but didnt see it but maybe on 10 it could be.

I was looking on the patio area to the left hand side but didnt find it there.

I did leave my contact details to the hotel manager and I printed some flyers gave one to the receptionist and also posted a few around the street, but no one contacted me.

I will go to the hotel again maybe it is still there who knows

Thanks a lot for your help!

Dan

 

[Cyberpower678]

Hi Cyberpower,

Thanks a lot for checking. So number 10 is the last point it should be? When i was there went to the top terrace and tried to look down on patio 9 but didnt see it but maybe on 10 it could be.

I was looking on the patio area to the left hand side but didnt find it there.

I did leave my contact details to the hotel manager and I printed some flyers gave one to the receptionist and also posted a few around the street, but no one contacted me.

I will go to the hotel again maybe it is still there who knows

Thanks a lot for your help!

Dan

No problem. The return to home was not engaged during flight. It looks like you may have flown it into the building by mistake.

 

[msinger]

So number 10 is the last point it should be?

Yes.

 

[msinger]

Unfortunately I think I got close to a building, suddenly i lost the video feed and connection to the Mavic and got a message that it was doing a RTH

Your flight log does not show RTH was initiated. It looks like you were in full control the entire time.

If this was caused by a malfunction of the device it would be the only way DJI might be able to help me.

Your flight log shows you steered your Mavic sideways into the side of the building. I don't see any signs of a malfunction.

 

[d2fino]

Hi Msinger,

I was in control until it suddenly lost the RC signal, the screen went black and the controller started beeping and i had no control anymore, but i clearly remember seeing a message on the screen about RTH and then something about motor obstruction.

My theory is perhaps some interference caused it to loose GPS and RC link, then it may have tried to initiate a RTH and crashed.

On the DJI go app flight record, I can see when it gets close to the building it shows weak GPS signal then seems to start spinning and then shows the message motor obstructed and that the last.

Given that it seemed to be having issues to calibrate it, i think it could be an issue with the software, and it was not like this before I upgraded the mobile app.

I dont know if DJI will admit to be a fault with the device if its easier to deem it as a user accident.

Its a long shot but i will go to the hotel tomorrow and hope i can still find it, otherwise i dont know what DJI will do

Thanks

 

[Cyberpower678]

Hi Msinger,

I was in control until it suddenly lost the RC signal, the screen went black and the controller started beeping and i had no control anymore, but i clearly remember seeing a message on the screen about RTH and then something about motor obstruction.

My theory is perhaps some interference caused it to loose GPS and RC link, then it may have tried to initiate a RTH and crashed.

On the DJI go app flight record, I can see when it gets close to the building it shows weak GPS signal then seems to start spinning and then shows the message motor obstructed and that the last.

Given that it seemed to be having issues to calibrate it, i think it could be an issue with the software, and it was not like this before I upgraded the mobile app.

I dont know if DJI will admit to be a fault with the device if its easier to deem it as a user accident.

Its a long shot but i will go to the hotel tomorrow and hope i can still find it, otherwise i dont know what DJI will do

Thanks

When I looked at the log, it shows that the RC was sending a signal all the way up to the crash. The signal I say was the stick controlling sideways movement was being held in and it moved sideways into the hotel and crashed. The RTH message you say was a prompt to initiate RTH.

 

[msinger]

Given that it seemed to be having issues to calibrate it, i think it could be an issue with the software, and it was not like this before I upgraded the mobile app.

There's no need to calibrate the compass before every flight. If you calibrate in an area that contains magnetic metal objects (e.g. a fence or concrete), you could save a bad calibration that causes erratic flight after takeoff. You did not note that you had trouble controlling your Mavic after takeoff, so I assumed that was not the case here.

 

[AlanTheBeast]

Just another view. Colour me a sadist.

P-mode with OA off?

 

[d2fino]

@Cyberpower678

I did remeber seeing this RTH prompt and am sure I accepted it so i expected it to return but then i saw the message about motor obstructed so I realise it w

When I looked at the log, it shows that the RC was sending a signal all the way up to the crash. The signal I say was the stick controlling sideways movement was being held in and it moved sideways into the hotel and crashed. The RTH message you say was a prompt to initiate RTH.

I did remember seeing this RTH prompt and am sure I accepted it so i expected it to return but then i saw the message about motor obstructed so I realise it was probably crashed

 

[d2fino]

There's no need to calibrate the compass before every flight. If you calibrate in an area that contains magnetic metal objects (e.g. a fence or concrete), you could save a bad calibration that causes erratic flight after takeoff. You did not note that you had trouble controlling your Mavic after takeoff, so I assumed that was not the case here.

Well when I started the app it asked to calibrate the drone where you do the turnaround thing, it seemed to be flying ok but i dont understand why i lost the video signal and i think most importantly this happened before the crash

 

[d2fino]

View attachment 8257

Just another view. Colour me a sadist.

P-mode with OA off?

Thank you Alan, this does seem to indicate it landed in the hotel in one of the terraces which i didnt look yet. My intitial assumption was that it fell all the way down to the pavement and some passer by must have took it

 

[Cyberpower678]

@Cyberpower678

I did remeber seeing this RTH prompt and am sure I accepted it so i expected it to return but then i saw the message about motor obstructed so I realise it w


I did remember seeing this RTH prompt and am sure I accepted it so i expected it to return but then i saw the message about motor obstructed so I realise it was probably crashed

You probably activated too late. But your aileron stick was registered as being held towards the left I believe. So the drone was moving in that direction. When you lose signal, the first to go is always the video.

 

[msinger]

i dont understand why i lost the video signal and i think most importantly this happened before the crash

It could have had something to do with the two rows of trees that were between you and your Mavic.

 

[AlanTheBeast]

View attachment 8258

Thank you Alan, this does seem to indicate it landed in the hotel in one of the terraces which i didnt look yet. My intitial assumption was that it fell all the way down to the pavement and some passer by must have took it

And it might have fallen to the pavement. That just shows the last bit of data received by your GO app. If the radio on the drone failed or an antenna broke off, then it may not be at that last "transmitted" location.

As you can see below, the last records from the drone are _moving_, not sitting still.

5.4 m/s is 20 km/hr... (Not sure if that is horizontal or combined 3 axes). Rate of descent in the last second was about 6 m/s downward - pretty constant / not accelerating (not free falling).

Rule nothing out. [1]



[1] It's even _plausible_ if very unlikely that after falling off the building it flew somewhere else but was no longer sending a signal due to damage.

 

[AlanTheBeast]

It could have had something to do with the two rows of trees that were between you and your Mavic.

View attachment 8263

I was looking at the same thing, but from another perspective, in the patch to the south of his home point the attenuation would not have been so bad.

OTOH, he is under CE emissions rules too...

 

[Cyberpower678]

I was looking at the same thing, but from another perspective, in the patch to the south of his home point the attenuation would not have been so bad.

OTOH, he is under CE emissions rules too...

View attachment 8264

Terrible rendering.

 

[AlanTheBeast]

Terrible rendering.

I'm doing this on a TRS-80 . Not bad I'd say