Started my mavic 2 zoom for a routine flight and within seconds it fell out of the sky and was destroyed.  How can I figure out what happened up there?

http://www.phantomhelp.com/LogViewer/Upload/   Use this link and come back here post log .

Here it is: https://www.phantomhelp.com/LogViewer/T420PYALOGVPONUC9DJ4/  

This is very odd looking.

No sudden pitch,roll or yaw movements in the end should mean that nothing hit it or a prop/engine failed. Nothing suspicious regarding cell voltage deviation that could indicate a battery cell failure either. The TXT logs only ends either when motors stops, the GO4 app crashes, mobile device gets disconnected from the RC or if it's a RC-AC disconnect.

So in the end of the log you gave the AC all ... full throttle & elevator, then at 44m height with a heading speed of 18m/s the log abruptly stops without any indicated disconnection to the RC. All this indicates a sudden power loss ... the battery disconnected.

Did you let of the sticks just when it happened ... did the AC went silent?

Click on the chart to make it larger ... explanations to the graphs below the chart.

slup Posted at 4-1 12:54
No sudden pitch,roll or yaw movements in the end should mean that nothing hit it or a prop/engine failed. Nothing suspicious regarding cell voltage deviation that could indicate a battery cell failure either. The TXT logs only ends either when motors stops, the GO4 app crashes, mobile device gets disconnected from the RC or if it's a RC-AC disconnect.

So in the end of the log you gave the AC all ... full throttle & elevator, then at 44m height with a heading speed of 18m/s the log abruptly stops without any indicated disconnection to the RC. All this indicates a sudden power loss ... the battery disconnected.

It is a very nice, and busy chart, but I do not know how anyone could make any sense of it.

I think the battery popped out because I found the drone in the street, but the battery  up and out in the field buried in the dirt.  What kind of velocity could cause the battery to shoot so much farther than the drone?  Probably, when I increased the speed dramatically at the end is right when the battery popped off.  Is this possible?

I was flying very normal making sure to head to the field when suddenly the screen said weak signal froze and went grey.

Blellow Posted at 4-1 13:54
I think the battery popped out because I found the drone in the street, but the battery  up and out in the field buried in the dirt.  What kind of velocity could cause the battery to shoot so much farther than the drone?  Probably, when I increased the speed dramatically at the end is right when the battery popped off.  Is this possible?

I was flying very normal making sure to head to the field when suddenly the screen said weak signal froze and went grey.

I think the battery popped out because I found the drone in the street, but the battery  up and out in the field buried in the dirt.   ...

Probably, when I increased the speed dramatically at the end is right when the battery popped off.  Is this possible?
Batteries commonly become dislodged in collisions, so finding the battery separated from the drone is not conclusive.
Batteries also can be dislodged in flight if the battery has swollen so that it doesn't properly latch in position.
This is often related to hard flying and sudden changes in control input.

Another battery issue looks to be at least part of the problem.
How long had that battery been sitting around since it was charged?
The data shows the battery at 84% to start but unless you have a fully charged battery, the % indication will be incorrect.
Your battery cell voltages  were acceptable when hovering  for the first 13 seconds of the flight.
But under load, flying hard in Sport Mode they had fallen substantially just 17 seconds later.

What kind of velocity could cause the battery to shoot so much farther than the drone?  
The drone was flying at 40.4 mph when the data ends.

Labroides can have a point there regarding a battery that have been laying around before used ... looking at the 4 different cell voltage levels in relation to the battery % it indeed looks suspicious, but can also be hard to judge as it's normal for the voltage to initially drop when pushing the AC full out in Sport mode.

At motor start you had 95% battery and the cell voltage were around 4,2v in all cells which is normal for a "full" battery. A 50% battery should correspond to approx 3,7v in each cell ... but here, in the end of the log, the cells are down to around 3,6v with a battery on 93%. But again, this alone doesn't necessarily mean that they shouldn't have recovered voltage wise if the flight had proceeded as normal.

If you can get hold of the mobile device DAT log we perhaps can see more ... as that log runs until power off, not only to motor stop as the TXT log.

The DAT log from this flight have FLY096.DAT in the end ... and you can find it here:

In iOS :
Apps » DJI GO 4 » FlightRecords » MCDatFlightRecords

In Android :
DJI » dji.go.v4 » FlightRecord » MCDatFlightRecords

Below the Battery cell behavior vs. Battery % ...

Geebax Posted at 4-1 13:39
It is a very nice, and busy chart, but I do not know how anyone could make any sense of it.

...but I do not know how anyone could make any sense of it.

Not hard at all if you take your time to read it ... that chart tells us that there wasn't any quick AC movements in either axis that could correspond to it hitting something or a motor/prop failure.

All look normal considering how the AC was maneuvered ...

This makes it more probable that it could have been a power loss due to some reason instead.

Since you recovered drone, you could try to get log information from drone (itself) for others to look at; along with sending drone into DJI for analysis.

Assuming you can get log information from drone, and log information ends abruptly like log information from SmartDevice; it would point to sudden loss of power.  If you can't get drone to power-up to point to access log information, then crash could be result of drone's processor failing in flight or being damaged on impact.  With later possibly caused by sudden loss of power in flight.

Would be helpful if Mavic's processor had a tiny battery (or capicator) which provided enough power to keep processor going long enough to detect and report - sudden loss of power (battery pack disconnect).

Blellow Posted at 4-1 13:54
I think the battery popped out because I found the drone in the street, but the battery  up and out in the field buried in the dirt.  What kind of velocity could cause the battery to shoot so much farther than the drone?  Probably, when I increased the speed dramatically at the end is right when the battery popped off.  Is this possible?

I was flying very normal making sure to head to the field when suddenly the screen said weak signal froze and went grey.

Labroids is correct batteries do pop out on impact, it was a power failure, if battery was lying around for more than 10 days it would not show above 60% , this does not mean it would not have been below its reading, I have also seen batteries not put in correctly to loosen through vibration but Mavic has a warning for this.
I recommend you send into dji and see what they say, if you have craft dji should be able to tell you more from .dat file.
Good luck.

I set my batteries to a 2 day discharge.  Huge bummer losing the M2 from this not being understood prior.  A lot of things in life aren't completely understood and only known of its existence after things have already unfolded.

HedgeTrimmer Posted at 4-2 03:55
Since you recovered drone, you could try to get log information from drone (itself) for others to look at; along with sending drone into DJI for analysis.

Assuming you can get log information from drone, and log information ends abruptly like log information from SmartDevice; it would point to sudden loss of power.  If you can't get drone to power-up to point to access log information, then crash could be result of drone's processor failing in flight or being damaged on impact.  With later possibly caused by sudden loss of power in flight.

...you could try to get log information from drone (itself)

That AC DAT log from a M2 is unfortunately encrypted & can't be read by any other than DJI staff.

But the mobile device DAT log is almost as useful & contain nearly the same signals ... though gathered in a lower frequency.

I found the drone immediately after the disconnecton Smoke Valley Street. I was that close.  The battery I did not find until the third attempt to look because it was way out in the field buried in the dirt.  It had to disconnect in the air to be that far from the drone and to totally avoid the street.  

I sent it out to dronenerds.  Its two years old and showing its age. I doubt they can fix it.  I might switch to autel evo 2 because their batteries are much more secure.

Please, if you have a two year old mavic 2 and old batteries,  the battery might shoot off at anytime!  Secure it! I thought the spark only had this problem but many mavic user have it too.

Blellow Posted at 4-2 10:37
https://bw-1651cf0d2f737d7adeab84d339dbabd3-gallery.s3.amazonaws.com/images/image_2931627/1ddd1217485b2538945426497d3aa591_original.jpg[/img]

I'm not surprised by that distance ... if this were a battery that started to rapidly swell during that full stick Sport amp draw it will for sure eject out with additional speed to that the AC had.

Blellow, I am sorry to hear about the accident. Please kindly send in the drone for service, free data analysis will be offered if the drone is within the warranty period, we will provide the corresponding offer to you based on the analysis result. Please start the service request at https://repair.dji.com/repair/index?site=brandsite&from=nav

Hi, thanks.  I'm pretty depressed about the loss of my drone, after I had taken great care of it for two years.  I sent it to dronenerds last week.  They are an authorized repair for DJI.  Should I have them do the data analysis?   Since, I had it for two years is there anything DJI can offer to help me replace my drone?

That is terrible, I am sorry.

Thanks.  Continued this conversation on mavicpilots, but the fool sar104 blamed me for the accident and got the thread locked.  What a tool.

Can help but notice that the new Mavic Air 2 has METAL CLAMPS on the batteries for better security.   One more advantage to the Mavic Air 2.