Hello guys,

Here is my bad experience on the first day of use of my Mavic pro...

During a flight on Wednesday, March 22, I suddenly lost the connection with the drone that was 737 meters away from me in a relatively open space. A message was displayed stating that the signal was lost. The RTH altitude was set on 40m but the drone never returned... The drone flew at more than 140 meters from the ground, there were no obstacles, the Weather was clear and the gps signal excellent. After more than 2h of search around the last point recorded on the map, I finally found it but without the battery !!! I later found this last something like 10 meters away completely exploded and swollen ! (See the attached picture of the battery)

Maybe the battery disconnected from the drone before the fall. How could this be possible? Could the lithium battery had a defect and inflate or explode, which would have led to its disconnection of the drone? It was the first flight with this new battery, received at the same time than the drone in the flymore pack. I had already done 2 flights just before with the 2 other new batteries wihtout any problems. They had been loaded all three at the same time on the hub. When the contact was lost, the drone was flying for 3:23 minutes and the battery was at 88% charge. Is this a problem already seen on this drone?




I am really stunned by what happened, I do not understand how the battery could have disconnected from the drone... Or maybe the battery disconnected from the drone after the impact on ground, but why did the drone felt on the ground like a stone after RC signal lost ??? Does this has already occurred ?




I turned the problem in all directions and I can not find an explanation if it is not a material damage, which would also explain that the RTH function did not work.

Here is my log file : https://app.airdata.com/main?fli ... amp;page_id=GENERAL

My retailer from France has opened a ticket at Dji services for log analysis more than 3 weeks ago but my retailer and I still don't have any news. Is there anybody from Dji who could help me ?

Thanks a lot.

Does your Mavic still work, with a different battery? If so, you can get the .dat file from the Mavic and post it here. Some of us can try to take a look and analyze it for you.

Can you also post the manufacturing date of your Mavic? You can find the date by using this: http://djiserialdecoder.x10host.com/

Wow thats crazy, do you think it exploded in air?

" but why did the drone felt on the ground like a stone after RC signal lost ??? Does this has already occurred ?"

Unfortunately, there have been a handful of cases where this seems to have happened recently.

BTW, how sure are you that you had clipped the battery in securely?

Hello

Could be insterresting to discuss about your Issue on :

http://www.djiphantom-forum.com/c46-le-mavic

A bientôt....

It's still a mystery why it didn't RTH , from those logs all you can tell is you were in an area when taking off of high interference, there are power lines right in front of you, I suspect this is where interference was coming from, the end of your flight seemed to be on a road and I suspect you battery was damaged when it hit that road.
You had good gps and your battery cells were fine and normal, I don't think you didn't insert the battery properly, it almost impossible to start up the Mavic if the battery is not in 100%.

The worrying thing about this sort of crash is, if you have radio signal failure then aircraft should revert to RTH and it didn't , so it's very important to everyone to know exactly what has happened in a case like yours, so keep us informed as to dji's findings.

Good luck...

Let me ask you this did you notice your Controller signal flashing  on controlller display ,they tell  me if you see this it is interference.

FrequentFlyer Posted at 2017-4-18 07:16
Wow thats crazy, do you think it exploded in air?

Given the state of the battery after the crash, this could be an explanation ... But I'm not sure of anything. This crash is a real mystery.

Jason Lane Posted at 2017-4-18 07:01
Does your Mavic still work, with a different battery? If so, you can get the .dat file from the Mavic and post it here. Some of us can try to take a look and analyze it for you.

Can you also post the manufacturing date of your Mavic? You can find the date by using this: http://djiserialdecoder.x10host.com/

Here is the manufacturing date : Tuesday, March, 7th 2017

My Mavic still work with another battery, but can't fly because the propellers, the right front arm and the gimbal plate are broken or damaged.
I'im going to get the .dat file and post it here.

Personally i don't think your battery exploded in the air and telling by the photo it looks like an impact from a crash.
I do notice that around 500m from your further flight distance there is a large plant of Siemens VAI.
From the wiki page it's says that they produce Carbon and Stainless steel.
Maybe the large amount of steel/iron around that place did confuse the gps of your drone.

hallmark007 Posted at 2017-4-18 09:06
It's still a mystery why it didn't RTH , from those logs all you can tell is you were in an area when taking off of high interference, there are power lines right in front of you, I suspect this is where interference was coming from, the end of your flight seemed to be on a road and I suspect you battery was damaged when it hit that road.
You had good gps and your battery cells were fine and normal, I don't think you didn't insert the battery properly, it almost impossible to start up the Mavic if the battery is not in 100%.

You're right! There are power lines 300 meters in my back but not in the direction of the flight. That is certainly why the notification of wireless interference only appear one time at the take off but never again after.

I'm sure the battery has been properly locked. After the crash, I tried to start the Mavic while trying to insert another battery incorrectly, and it's almost impossible.

Spektre Posted at 2017-4-18 13:07
You're right! There are power lines 300 meters in my back but not in the direction of the flight. That is certainly why the notification of wireless interference only appear one time at the take off but never again after.

I'm sure the battery has been properly locked. After the crash, I tried to start the Mavic while trying to insert another battery incorrectly, and it's almost impossible.

Nothing in your logs show this is anything to do with pilot error, there are failsafe procedures for the warnings you received, this will be a matter for dji to explain what was the cause.

Mcflying Posted at 2017-4-18 12:59
Personally i don't think your battery exploded in the air and telling by the photo it looks like an impact from a crash.
I do notice that around 500m from your further flight distance there is a large plant of Siemens VAI.
From the wiki page it's says that they produce Carbon and Stainless steel.

I've found the battery on a quite soft ground, in a vegetable garden, not on a hard paved road. That's why there's a kind of mystery around this...

The Siemens plant is quite far from the crash site. It's 800/1000m away and their job is to manufacture machines for the metallurgical industry. I'm pretty sure there is no link with this.

Thanks for your advice.

Jason Lane Posted at 2017-4-18 07:01
Does your Mavic still work, with a different battery? If so, you can get the .dat file from the Mavic and post it here. Some of us can try to take a look and analyze it for you.

Can you also post the manufacturing date of your Mavic? You can find the date by using this: http://djiserialdecoder.x10host.com/

Hi Jason,

I have a problem retrieving dat file from my Mavic. When i try to copy the dat files from the mavic to my macbook, using the method of datfile.net, i have the following message (translated from the french) :

"The Finder can not complete the operation because some data of "FLY020.DAT" can not be read or written.
(Error code -36)"

It's the same message for all the dat files.

Any solution ?

Thanks.

Spektre Posted at 2017-4-19 01:07
Hi Jason,

I have a problem retrieving dat file from my Mavic. When i try to copy the dat files from the mavic to my macbook, using the method of datfile.net, i have the following message (translated from the french) :

I've never encountered that myself. Did you try both methods given on that page?

Just a thought. Someone posted an interesting post regarding battery not fitting the drone very well. They apparently click on but there is a significant gap or slack . looks lik there could be a fabrication issue with some batteries.

Spektre ,
             Sorry to hear about your misfortune -- In my opinion there is a possibility that you battery did pop out of the Mavic if it was faulty --- Lipo batteries fail in 3 ways :
1- The contacts between the cells can open ( disconnect ) causing either not putting out its rated power
    or not having any output power at all but leave's the battery looking normal.
2- The battery can Short out causing it to EXPAND with force causing the housing it is mounted in to break
    and pop out of what ever it is mounted in <--- this is what I believe you may have experienced
3- Catastrophic failure causes the battery to Short out Expand braking what ever it's mounted in along
    with Bursting into Flames
This mishap you had is something DJI will have to examine to determine what actually happen
Don't throw that battery out -- I'm sure DJI will want it
I Hope it all goes your way      

It is quite obvious it didn't explode as it's not burnt anywhere.  Explanations regarding battery bloat don't seem correct as anybody who has had a batter bloat knows it stays that way for quite some time.  It would be quite obvious when found that it was bloated.  It has to be damage from impact, there's no other way around it.  The location where the battery was found is less important that what else is around the location.  This can very easily, and most likely be, the result of a battery being flung out of the Mavic when it crashed, or falling out of the Mavic during flight.  Either way, the logs are going to be very important.

That is very interesting. Keep us updated if you post into another forum or the outcome. Because I now believe there may be an issue with the batteries.

I had my Mavic Pro for less than 2weeks and 3/29 I was flying in an area I normally fly near my apartments the Drone was in sight and then it appeared as if it had been shot out out air because it did an immediate nose dive which damaged the front body and gimbal. I though maybe I snagged a light colored power line that was to thin to see, or the avoidance system was off.

The Drone was less than 40 yards from me in a field. When I went to retrieve the Mavic the battery was detached and not near the Mavic and I searched for 15mins and found the battery 5 yards in the opposite direction of the crash.

I was puzzled because DJI Drone Pilots say the Mavic is uncrashable I purchased DJI Don't Care and paid the $79.00 and still have no idea whenever I will get it back, but the point being if their is a battery issue like Samsung I need a refund and the option to return my Mavic for a refund. We need to research and see if any other people have had this issue.  

I do understand your pain shell out $1,100 and you can't fly and DJI Care takes 6-8 weeks with a replacement fee of 1st $79 2nd $129.

fans62c045a1 Posted at 2017-4-20 04:22
That is very interesting. Keep us updated if you post into another forum or the outcome. Because I now believe there may be an issue with the batteries.

I had my Mavic Pro for less than 2weeks and 3/29 I was flying in an area I normally fly near my apartments the Drone was in sight and then it appeared as if it had been shot out out air because it did an immediate nose dive which damaged the front body and gimbal. I though maybe I snagged a light colored power line that was to thin to see, or the avoidance system was off.

Perhaps someone here could shed some more light on what happened with your flight if you post the log from it as the OP did his.

DJI Drone Pilots say the Mavic is uncrashable

Out of curiosity, who is "DJI Drone Pilots" and when / where did they say this?

method007 Posted at 2017-4-20 04:15
It is quite obvious it didn't explode as it's not burnt anywhere.  Explanations regarding battery bloat don't seem correct as anybody who has had a batter bloat knows it stays that way for quite some time.  It would be quite obvious when found that it was bloated.  It has to be damage from impact, there's no other way around it.  The location where the battery was found is less important that what else is around the location.  This can very easily, and most likely be, the result of a battery being flung out of the Mavic when it crashed, or falling out of the Mavic during flight.  Either way, the logs are going to be very important.

Method,
           Lipo's don't have to burn up when they fail -- The cause of a lipo expanding can be from over heating when discharging -- and it never returns to normal size , it will just get worst over time and eventually cause it to Burn up in Flames --- and yes the battery is damaged from the fall ( No doubt about that ) the op said the battery landed in a garden with lose dirt But the last tracking of his Mavic shows that it crashed in a street?
The battery expansion does concern me -- I'm giving the op the benefit of the doubt
The Mavic battery is pretty Tuff yet at the same time a good blow to it will also cause expansion
To me this is a tossup case only DJI can confirm
   

SkunkWerxs Posted at 2017-4-20 04:31
Method,
           Lipo's don't have to burn up when they fail -- The cause of a lipo expanding can be from over heating when discharging -- and it never returns to normal size , it will just get worst over time and eventually cause it to Burn up in Flames --- and yes the battery is damaged from the fall ( No doubt about that ) the op said the battery landed in a garden with lose dirt But the last tracking of his Mavic shows that it crashed in a street?
The battery expansion does concern me -- I'm giving the op the benefit of the doubt

I agree with you that the battery never returns to normal size once bloated.  That's why, based on the photos showing the battery not bloated, I said that it's unlikely that the battery bloated.

The battery can easily be flung a very far distance as the Mavic smashes into the ground, flips, and flings the battery like a trebuchet.  

Spektre, looking at the map on Airdata, the area where it disconnected seems to be bordering between fields on one side, and a residential area on the other. It looks like some of the houses have walls around them. Is it possible the Mavic crashed onto the top of a wall? That could account for the battery and Mavic traveling far from each other after impact. Perhaps you could show us a map with the locations where the Mavic and battery were found.

5 weeks after the crash, my french retailer finally got some news from DJI... They ask him to send them de DAT file from the Mavic (FLY019.DAT). After several tries to get this, encountering problems with the "Error code -36" on my macbook pro, i don't know how but i finally managed to get this file from the Mavic with DJI assistant 2 and the Flight Data tool.

Here is the file if some of yours want to have a look at it : https://drive.google.com/open?id=0B6jZfgnep8rAeV9NUE10MmUzR2s

Thank for your help!

Jason Lane Posted at 2017-4-19 22:28
I've never encountered that myself. Did you try both methods given on that page?

Hi Jason,

I finally managed to get the DAT file from the mavic if you want to have a look at it, or if you know someone who can analyse it. : https://drive.google.com/open?id=0B6jZfgnep8rAeV9NUE10MmUzR2s

My retailer has transferred this file to DJI last week and i'm now waiting for some news.

Thanks!

Spektre Posted at 2017-5-2 08:35
Hi Jason,

I finally managed to get the DAT file from the mavic if you want to have a look at it, or if you know someone who can analyse it. : https://drive.google.com/open?id=0B6jZfgnep8rAeV9NUE10MmUzR2s

I took a quick look for you, and I can see that it seems to confirm that the power failed abruptly during flight, and there didn't seem to be anything wrong before the loss occurred. If one of the real experts gets to take a look at your file, they may be able to give a little further insight, but I think overall there's not much more that the log can tell us. In all the other cases of inflight power failures that I've tracked, the root cause remains a mystery, unless DJI's engineers have managed to pinpoint something with more in-depth analysis.

I do hope DJI agrees to a warranty replacement, as they have recently done for a few others with similar cases.

Jason Lane Posted at 2017-5-4 07:14
I took a quick look for you, and I can see that it seems to confirm that the power failed abruptly during flight, and there didn't seem to be anything wrong before the loss occurred. If one of the real experts gets to take a look at your file, they may be able to give a little further insight, but I think overall there's not much more that the log can tell us. In all the other cases of inflight power failures that I've tracked, the root cause remains a mystery, unless DJI's engineers have managed to pinpoint something with more in-depth analysis.

I do hope DJI agrees to a warranty replacement, as they have recently done for a few others with similar cases.

Hi Jason,

Thanks for your opinion and the time you spent to analyze the log file.

I really hope DJI will agree for a warranty replacement.

One and a half month that the crash occured. I have to say DJI support service is very very slow ...

I'll keep you informed when i'll have some news.