I lost my Mavic over water as it was on the way back to home point when the low battery warning started sounding at 35%,. My critical warning was set at 15%.
When I was trying to fly it back, the reverse flight was very slow, yetthe battery level was dropping.  It was a windless calm night.  So slow such that it reached almost to shore and the Mavic auto landed in water!

DJI team, what's my recourse?
Thanks!

ay6810,

Sorry to hear you went down
I believed the did do its job correctly
One of the characteristic's of a Lipo battery is that it maintains constant output of
Voltage and Amperage and will continue to do so very slowly to a certain point as it
feeds the load put on it, once it drains to its lowest point the Volt and Amp's drop off
very quickly opposed to Nickel metal batteries where they constantly deplete Volts and
Amps consistently as they feed the load, draining much quicker with an inconsistency of
Volts + Amp's  This is why we use Lipo's they last much longer
If you post your flight data I'm sure a Mod would be able to forward it to DJI's engineers
To see if the battery was pushed beyond it's limit or if it was Defective.
Best Wishes
                  Fly Safe -- Fly Free

Are these the flight data in txt format?

ay6810 Posted at 2017-4-9 06:33
Are these the flight data in txt format?

Are these the flight data

No. Upload the log from your last flight using the instructions here and provide a link.

As SkunkWerxs mentioned, the battery consumption isn't necessarily linear; in other words, the last (for example) 20% of the battery may be used more quickly than the first 20%.

And I know that you said it was a "windless calm night", but the wind at ground level is often very different from what the Mavic experiences, especially at the altitudes you'd normally use for RTH. So it is possible that it was fighting the wind on the return trip.

Hi , I managed to upload this data into healthydrones and it came out with this... my Home point was changed by itself and at point J, it went ATTI.
Not sure why there's 2 logs so here they are.  I flew consecutively and Mavic didn't return or relaunch.


http://app.airdata.com/main?share=jJDdPX

This was the second part where the Mavic autolanded in the water despite me trying to get it back to land.

http://app.airdata.com/main?share=MaCTrO

ay6810 Posted at 2017-4-10 02:33
Hi , I managed to upload this data into healthydrones and it came out with this... my Home point was changed by itself and at point J, it went ATTI.
Not sure why there's 2 logs so here they are.  I flew consecutively and Mavic didn't return or relaunch.

it went ATTI.

"GPS_Atti" is the normal (non-sport) flight mode, a.k.a. "P-mode". I only see it switching between that and "Go_Home" (RTH) mode in the logs you provided, and RTH was triggered because of a low battery.

Not sure why there's 2 logs so here they are.

Yes, that is odd; I don't remember seeing that before.

It looks like you got your first low battery warning several minutes earlier (at 19:40), at which point you continued flying northwest across the river and away from the eastern shortline. Then you started flying northeast more or less parallel to the opposite (western) shoreline -- but still over water -- and continued until your Mavic went down at around 23:36.

It would have been a good idea to land on the western shoreline to which you were apparently fairly close for the last flew minutes of your flight, but it looks to me like you just flew over the water until you had no more battery power left.

Could you please provide me with your DJI account email and the date this occurred?
I'll help to review your flight records.

DroneFlying Posted at 2017-4-10 02:48
it went ATTI.

"GPS_Atti" is the normal (non-sport) flight mode, a.k.a. "P-mode". I only see it switching between that and "Go_Home" (RTH) mode in the logs you provided, and RTH was triggered because of a low battery.

Not sure why there's 2 logs so here they are.

Yes, that is odd; I don't remember seeing that before

Hey DroneFlying,

                 About his two log's for the same flight ---- Could he have had a power disconnect ? (Glitch)
this is the only probability that comes to mind , I think it will cause the Mavic to have 2 log's  --- The other
thing is the flight path's almost look the same.

   

DJI Mindy Posted at 2017-4-10 03:20
Could you please provide me with your DJI account email and the date this occurred?
I'll help to review your flight records.

Hi Mindy, I have sent you a PM. Please review. Thanks.

DroneFlying Posted at 2017-4-10 02:48
it went ATTI.

"GPS_Atti" is the normal (non-sport) flight mode, a.k.a. "P-mode". I only see it switching between that and "Go_Home" (RTH) mode in the logs you provided, and RTH was triggered because of a low battery.

I didn't want to fly parallel to the water or western shoreline as I pulled back on the right  stick to make it come back but it went forward instead as you saw on the second flight log.  The Mavic was not facing me but its rear LED glowing brightly was facing me.  I tried to make it reverse back but the speed was very very slow.  It usually doesn't exhibit this behaviour when flown.

Not sure if this would have helped you at all but having your RTH set lower would have considerably lowered the time it took the mavic to cimb too RTH altitude and start heading home. This usually wouldn't matter but when your battery is at 10% those seconds are precious.

SkunkWerxs Posted at 2017-4-10 03:51
Not sure why there's 2 logs so here they are.

Yes, that is odd; I don't remember seeing that before

Could he have had a power disconnect ?

That's as good a theory as anything I can think of. I suppose that a loss of power on the controller or killing the app and restarting it might generate multiple flight logs and I just had never realized it before.

Although it would be easy to state pilot error on this case with what we have seen so far, such as ignoring return to home and staying over the water, there are inconsistencies that are making me think that this aircraft was malfunctioning and that the pilot maybe had very little control at making it move properly.  I hope that DJI sort this out for you.

ay6810 Posted at 2017-4-10 04:02
I didn't want to fly parallel to the water or western shoreline as I pulled back on the right  stick to make it come back but it went forward instead as you saw on the second flight log.  The Mavic was not facing me but its rear LED glowing brightly was facing me.  I tried to make it reverse back but the speed was very very slow.  It usually doesn't exhibit this behaviour when flown.

Well, if that's the case then it's something DJI may be able to confirm, in which case they'd probably offer a warranty replacement. Good luck and let us know how this turns out.

ay6810 Posted at 2017-4-10 03:54
Hi Mindy, I have sent you a PM. Please review. Thanks.

Sorry, I didn't receive your PM. It's not always working.
Is your DJI account email the same as your forum email? Besides, did you recover the drone?

Please also send an email to support@dji.com with your DJI account email and the date this occurred.

Our support team will help to create a case for you and our engineers will analyze the data and let you know what could have caused the issue.

DJI Mindy Posted at 2017-4-10 22:20
Sorry, I didn't receive your PM. It's not always working.
Is your DJI account email the same as your forum email? Besides, did you recover the drone?
Please also send an email to support@dji.com with your DJI account email and the date this occurred. Our support team will help to create a case for you and our engineers will analyze the data and let you know what could have caused the issue.

Yes the DJI account uses the same email.  No, the Mavic was lost and sank into the water. I have created a case with  support@dji.com and they are asking for the RC logs.

DJI Mindy Posted at 2017-4-10 22:20
Sorry, I didn't receive your PM. It's not always working.
Is your DJI account email the same as your forum email? Besides, did you recover the drone?
Please also send an email to support@dji.com with your DJI account email and the date this occurred. Our support team will help to create a case for you and our engineers will analyze the data and let you know what could have caused the issue.

Hi Mandy, there was no acknowledgment from DJI Support on the log files being received. How long do we usually have to wait? Thanks.

DroneFlying Posted at 2017-4-10 04:50
Well, if that's the case then it's something DJI may be able to confirm, in which case they'd probably offer a warranty replacement. Good luck and let us know how this turns out.

The reply given by DJI:
Thank you very much for your valued reply.

Here is the result of the data analysis:

At the flight time of 04:59, 249m away from the home point, battery owns 21% power, the APP triggered low battery RHT, while the pilot canceled it at that time.

At the time of 06:21, 56m above and 169m away, pilot required to RTH by RC when the battery is 14%. The pilot set 100 m as the height of RHT. The aircraft started to ascend, during which the power of the battery can only enough to land.

Aircraft entered force landing mode at 06:51, pilot kept pushing pitch stick backward in landing mode, battery was used up and ended in to the water.

​
​
​
​
In a conclusion, there is no manufacturing error of the drone and it is the pilot operation error. For the first time of the APP showing to RTH, the pilot is supposed to choose RTH for safety flying.
There was no mention of why the MAVIC went to ATTI mode and DJI did not address the issue.  When I asked them again, DJI claims that
"The main reason of the flew away is that the pilot cancelled the RHT manually. ATTI mode is one of the working modes and design functions of the drone. We do not consider it as manufacturing error. Please note that. There is no wrong with the drone during the entire progress."

ay6810 Posted at 2017-4-26 17:11
The reply given by DJI:
Thank you very much for your valued reply.

"ATTI mode is one of the working modes and design functions of the drone. We do not consider it as manufacturing error."

If it went into ATTI mode during the flight I'd be very curious to hear DJI's explanation for how / why that happened and if they can't offer one that makes sense they should be willing to reconsider their decision on this.

P.S. Can you upload the relevant flight logs again but this time to PhantomHelp?

DJI Mindy Posted at 2017-4-10 22:20
Sorry, I didn't receive your PM. It's not always working.
Is your DJI account email the same as your forum email? Besides, did you recover the drone?
Please also send an email to support@dji.com with your DJI account email and the date this occurred. Our support team will help to create a case for you and our engineers will analyze the data and let you know what could have caused the issue.

Mindy, can you shed on any light on why the OP is being told that it's normal for his Mavic to go into ATTI mode when it's flying out in the open? Thanks.

ay6810 Posted at 2017-4-26 17:11
The reply given by DJI:
Thank you very much for your valued reply.

I have reviewed your flight records.
The drone was never switch to ATTI mode.
Sorry for the loss of your drone. Since you cancelled the RTH, the aircraft ended into water when the bettery was used up.

DroneFlying Posted at 2017-4-26 18:09
"ATTI mode is one of the working modes and design functions of the drone. We do not consider it as manufacturing error."

If it went into ATTI mode during the flight I'd be very curious to hear DJI's explanation for how / why that happened and if they can't offer one that makes sense they should be willing to reconsider their decision on this.

Yup, I'll do that.  Just read your message.

DroneFlying Posted at 2017-4-26 18:09
"ATTI mode is one of the working modes and design functions of the drone. We do not consider it as manufacturing error."

If it went into ATTI mode during the flight I'd be very curious to hear DJI's explanation for how / why that happened and if they can't offer one that makes sense they should be willing to reconsider their decision on this.

http://www.phantomhelp.com/LogViewer/4ADR03LCZL7HZS53KIUV/#

This is when i started flying...

http://www.phantomhelp.com/LogViewer/21AJZUI4XC38XK2VJ9RN/

This is when I got into the issues...of low battery.

Why is that that airdata analysed that I had a point where it went to ATTI mode?
The analysis by PhantomHelp seems different.

ay6810 Posted at 2017-5-3 18:53
http://www.phantomhelp.com/LogViewer/4ADR03LCZL7HZS53KIUV/#

This is when i started flying...

Why is that that airdata analysed that I had a point where it went to ATTI mode?

I don't believe it did; I think that was just a misunderstanding. I apologize if I made you think differently, but the response you posted from DJI support made me think maybe they had seen something to indicate that it had been in ATTI mode.

The analysis by PhantomHelp seems different.

The important parts are the same, but PhantomHelp does offer more and better information overall -- though I just noticed that Airdata has enhanced their output a little since the last time I looked.

DroneFlying Posted at 2017-5-5 05:08
Why is that that airdata analysed that I had a point where it went to ATTI mode?

I don't believe it did; I think that was just a misunderstanding. I apologize if I made you think differently, but the response you posted from DJI support made me think maybe they had seen something to indicate that it had been in ATTI mode.

ts ok as DJI never disputed in their direct replies to me that ATTI was never switched but they said Mavic going into ATTI mode is NOT a malfunction.

Its strange that airdata analyzes it as having gone ATTI at some point during return to home but Phantom Help says otherwise.
Anyway, they gave me 15% off the drone only price to appease their customer....

ay6810 Posted at 2017-5-5 16:39
ts ok as DJI never disputed in their direct replies to me that ATTI was never switched but they said Mavic going into ATTI mode is NOT a malfunction.

Its strange that airdata analyzes it as having gone ATTI at some point during return to home but Phantom Help says otherwise.

At least they gave you something off. Some other guys on forum said they got 30%