Mavic Air 2 - Sudden Power Loss & Fall

[Ach1905]

Hello drone mates,

I've read a lot in this forum and now I guess it's my turn to write about my experience.

I've recently bought the Mavic Air 2 and did fly it many times. The last time, the drone suddenly lost power and fell off. It was a mountain area, but I could find it.
If I remember well, it was about 20 meters high in hover mode, almost 15 meters away from me. Then my wife saw it suddenly fall from the sky. (I was walking towards a photo spot) I had zero warnings and this is driving me crazy.

I am losing my drone flying confidence as long as I don't understand what happened.

The drone was 1 week old. I fully charged all batteries before using them for the first time. the first and second batteries worked with no problems. The accident happened with the third one. (which I used then for the first time).

I don't think that it was a battery problem. It was fully charged and had about 60% power when the fall off happened after about 6 minutes of flight time.
When I found the drone, it was off and the battery was in the right place.

2 legs are badly broken, the gimbal as well.
At night I dared to turn it on and it worked. (didn't touch it since the accident). I still can connect it to my controller.

I took a look at the logs (I have some basic knowledge) but saw nothing weird so far. Maybe you could help me find out what happened?

Would DJI take this case?

 

[boblui]

The log provides no clues on the cause. The cell voltages were around 3.9 V which is normal and indicated that there was still a lot of battery ( 0% battery correspondes to 3.6V ). The log in the craft should provide more info but unfortunately the data can only be read by DJI. Seems that the battery just turned itself off. This is definitely covered by warranty. The only thing you can do now is to send it back.

 

[JLinSobe]

Ouch, I just bought the Mavic Air 2 thinking that it was more reliable than my Anafi.( Love It )

My experience has taught me that those “intelligent” batteries cause most of the power losses.

We had a series of crashes last year due to faulty battery firmware that was updated by our members.
Does it apply here?
I always screen-record my flights. That and the data logs can be of enormeus assistance in the event of a crash.
These are flying mini-computers and they have a single source of power, no backup!
I wish you the best resolution. I will be watching the outcome of a few cases of sudden drop.
Best Wishes!

 

[slup]

...I took a look at the logs (I have some basic knowledge) but saw nothing weird so far.

What you shared from Airdata.com isn't from a mobile device .TXT log ...

You have uploaded a .DAT log there & those will not be treated in a proper way. If the mobile device .DAT log is needed in the end we ask for it & we want that attached without being uploaded to any web-service.

Now ... find the mobile device log from this flight ending with .TXT ... go here & read up on how to retrieve --> Mavic Flight Log Retrieval and Analysis Guide (read under section 3.) ... attach then the log directly to a new post here with the "Attach files"-button.

 

[Ach1905]

The log provides no clues on the cause. The cell voltages were around 3.9 V which is normal and indicated that there was still a lot of battery ( 0% battery correspondes to 3.6V ). The log in the craft should provide more info but unfortunately the data can only be read by DJI. Seems that the battery just turned itself off. This is definitely covered by warranty. The only thing you can do now is to send it back.

Thanks for the reply! It definitely helped!
I will contact DJI.

 

[Ach1905]

What you shared from Airdata.com isn't from a mobile device .TXT log ...

You have uploaded a .DAT log there & those will not be treated in a proper way. If the mobile device .DAT log is needed in the end we ask for it & we want that attached without being uploaded to any web-service.

Now ... find the mobile device log from this flight ending with .TXT ... go here & read up on how to retrieve --> Mavic Flight Log Retrieval and Analysis Guide (read under section 3.) ... attach then the log directly to a new post here with the "Attach files"-button.

View attachment 121183

I uploaded both of DAT and TXT files now

 

[Steel63]

The log provides no clues on the cause. The cell voltages were around 3.9 V which is normal and indicated that there was still a lot of battery ( 0% battery correspondes to 3.6V ). The log in the craft should provide more info but unfortunately the data can only be read by DJI. Seems that the battery just turned itself off. This is definitely covered by warranty. The only thing you can do now is to send it back.

His airdata says 22% take off and 75 % landing or am I seeing things

 

[slup]

I uploaded both of DAT and TXT files now

Yep ... those 2 logs belongs to this flight.

And to have it said already from the beginning ... these 2 logs come from the mobile device, meaning that they will only record as long as the RC is connected to the MA2 ... & the mobile device is connected to the RC.

Furthermore ... the TXT log runs from motor start/stop + above. The DAT log from power on/off + above.

The log event stream from the TXT log indicate this at 393,6sec ... so what happens after 393,6sec is unknown.


If the MA2 still had a powered system after that the onboard DAT log would have continued to record. Unfortunately that DAT log is encrypted & can only be read by DJI.

Until the very last 10th of a second in the 2 available logs nothing abnormal is shown that are pointing to any kind of pilot error ...

Just there in the end you released the elevator stick at 391sec & a second later also the throttle stick, the MA2 was there at 8,1m above your HP. The MA2 pitched slightly up to break & at 392,9sec the vertical speed was 0m/s & horizontally just 0,3m/s & still slowing in to a complete hover. The last thing that's recorded is you applying full rudder input & the MA2 starts to alter the yaw angle ... then 393,6sec both logs ends abruptly.



It's equal with the motors according to the DAT log ... no abnormal current levels or deviations, & both the motor RPM's and command percentage indicate anything out of the ordinary.

Unfortunately this MA2 TXT show empty fields for the battery cell voltage (...again for a MA2). But dug out below 3 graphs from the DAT log. The lowest cell voltage just there where the log ends was healthy 3,9V with a total battery voltage of 11,85V ... indicating 72% remaining. So it's not a failing battery either.



So ... in the end much points towards a sudden power loss for either the whole aircraft of some crucial components. Can't see any cause to this in the logs at all, and if the MA2 had been lost DJI most probably had said that the cause was unknown & just offered you a maximum of 30% off a new MA2.

But lucky you ... you still have the aircraft to send in, that will give DJI access to the onboard DAT log, I'm pretty sure that the true reason can be read out there ... pointing it to pilot error will be very hard for them.

His airdata says 22% take off and 75 % landing or am I seeing things

He uploaded the mobile device DAT log to Airdata.com ... that always screw thing's up, Airdata is only good at dealing with TXT logs.

 

[Ach1905]

Yep ... those 2 logs belongs to this flight.

And to have it said already from the beginning ... these 2 logs come from the mobile device, meaning that they will only record as long as the RC is connected to the MA2 ... & the mobile device is connected to the RC.

Furthermore ... the TXT log runs from motor start/stop + above. The DAT log from power on/off + above.

The log event stream from the TXT log indicate this at 393,6sec ... so what happens after 393,6sec is unknown.

View attachment 121249
If the MA2 still had a powered system after that the onboard DAT log would have continued to record. Unfortunately that DAT log is encrypted & can only be read by DJI.

Until the very last 10th of a second in the 2 available logs nothing abnormal is shown that are pointing to any kind of pilot error ...

Just there in the end you released the elevator stick at 391sec & a second later also the throttle stick, the MA2 was there at 8,1m above your HP. The MA2 pitched slightly up to break & at 392,9sec the vertical speed was 0m/s & horizontally just 0,3m/s & still slowing in to a complete hover. The last thing that's recorded is you applying full rudder input & the MA2 starts to alter the yaw angle ... then 393,6sec both logs ends abruptly.

View attachment 121251

It's equal with the motors according to the DAT log ... no abnormal current levels or deviations, & both the motor RPM's and command percentage indicate anything out of the ordinary.

Unfortunately this MA2 TXT show empty fields for the battery cell voltage (...again for a MA2). But dug out below 3 graphs from the DAT log. The lowest cell voltage just there where the log ends was healthy 3,9V with a total battery voltage of 11,85V ... indicating 72% remaining. So it's not a failing battery either.

View attachment 121253

So ... in the end much points towards a sudden power loss for either the whole aircraft of some crucial components. Can't see any cause to this in the logs at all, and if the MA2 had been lost DJI most probably had said that the cause was unknown & just offered you a maximum of 30% off a new MA2.

But lucky you ... you still have the aircraft to send in, that will give DJI access to the onboard DAT log, I'm pretty sure that the true reason can be read out there ... pointing it to pilot error will be very hard for them.


He uploaded the mobile device DAT log to Airdata.com ... that always screw thing's up, Airdata is only good at dealing with TXT logs.

I noticed that too.
But as I read that DAT file handling by airdata is still in Beta mode and at the same time I saw such discrepancies in other DAT files from other pilots uploaded there, I knew it was a data handling problem.
Thanks for pointing that out!

 

[Ach1905]

Yep ... those 2 logs belongs to this flight.

And to have it said already from the beginning ... these 2 logs come from the mobile device, meaning that they will only record as long as the RC is connected to the MA2 ... & the mobile device is connected to the RC.

Furthermore ... the TXT log runs from motor start/stop + above. The DAT log from power on/off + above.

The log event stream from the TXT log indicate this at 393,6sec ... so what happens after 393,6sec is unknown.

View attachment 121249
If the MA2 still had a powered system after that the onboard DAT log would have continued to record. Unfortunately that DAT log is encrypted & can only be read by DJI.

Until the very last 10th of a second in the 2 available logs nothing abnormal is shown that are pointing to any kind of pilot error ...

Just there in the end you released the elevator stick at 391sec & a second later also the throttle stick, the MA2 was there at 8,1m above your HP. The MA2 pitched slightly up to break & at 392,9sec the vertical speed was 0m/s & horizontally just 0,3m/s & still slowing in to a complete hover. The last thing that's recorded is you applying full rudder input & the MA2 starts to alter the yaw angle ... then 393,6sec both logs ends abruptly.

View attachment 121251

It's equal with the motors according to the DAT log ... no abnormal current levels or deviations, & both the motor RPM's and command percentage indicate anything out of the ordinary.

Unfortunately this MA2 TXT show empty fields for the battery cell voltage (...again for a MA2). But dug out below 3 graphs from the DAT log. The lowest cell voltage just there where the log ends was healthy 3,9V with a total battery voltage of 11,85V ... indicating 72% remaining. So it's not a failing battery either.

View attachment 121253

So ... in the end much points towards a sudden power loss for either the whole aircraft of some crucial components. Can't see any cause to this in the logs at all, and if the MA2 had been lost DJI most probably had said that the cause was unknown & just offered you a maximum of 30% off a new MA2.

But lucky you ... you still have the aircraft to send in, that will give DJI access to the onboard DAT log, I'm pretty sure that the true reason can be read out there ... pointing it to pilot error will be very hard for them.


He uploaded the mobile device DAT log to Airdata.com ... that always screw thing's up, Airdata is only good at dealing with TXT logs.

Thank you so much for the detailed analysis!
I will contact DJI and send the MA2 back.
Will keep you guys posted

 

[Ach1905]

Hello guys!

An update after a discussion with DJI:

- They accepted to have the MA2 sent back to them and gave me a replacement a couple of days after. (thank you @slup for the great suggestion ;-) )

- I was insisting on knowing what happened, but they were not that transparent about it and briefly said that some electric circuits and switches were destroyed by a strong electromagnetic interference that was nearby.

That was true as I was flying near a radar. But I was not 100% satisfied with the answer because I was there with many other drones pilots and the accident happened only to me.

Lessons learned: there is a high risk of drone damage when you are close to a strong electromagnetic source.

Anyway, thank you guys for the great support!

 

[eaglesurfing]

Wow. Thanks for sharing that info.
Now we know to stay away from radar stations.

 

[boblui]

.... briefly said that some electric circuits and switches were destroyed by a strong electromagnetic interference that was nearby.....

Wow ! electronic hardware destroyed by electromagnetic interference . The military must be testing some kind of electromagnetic pulse weapons there. I have only seen them in movies.

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[TheCEO]

Hello guys!

An update after a discussion with DJI:

- They accepted to have the MA2 sent back to them and gave me a replacement a couple of days after. (thank you @slup for the great suggestion ;-) )

- I was insisting on knowing what happened, but they were not that transparent about it and briefly said that some electric circuits and switches were destroyed by a strong electromagnetic interference that was nearby.

That was true as I was flying near a radar. But I was not 100% satisfied with the answer because I was there with many other drones pilots and the accident happened only to me.

Lessons learned: there is a high risk of drone damage when you are close to a strong electromagnetic source.

Anyway, thank you guys for the great support!

Congrats man! I’m Happy DJI was able to work something out and get you a new one. That @slup seems to be very knowledgeable about these flight logs. Good luck with your new drone,enjoy!

 

[JulianHC]

I had an identical experience this morning. The drone suddenly lost power and descended rapidly from about 8m, fortunately into long grass. It is a new DJI Mavic Air 2, and the battery was more than half full. There is no radio or EMG interference on the hill where I fly. I restarted the drone and it flew normally for the rest of the battery charge. Very unsettling…

 

[JAW]

I had an identical experience this morning. The drone suddenly lost power and descended rapidly from about 8m, fortunately into long grass. It is a new DJI Mavic Air 2, and the battery was more than half full. There is no radio or EMG interference on the hill where I fly. I restarted the drone and it flew normally for the rest of the battery charge. Very unsettling…

if you want to know what happened, I would make your incident as separate post And let the gurus here figure out what happened.