Why did my Mavic 2 zoom fall out of the sky

[Perspective Drones]

Hello everyone! I joined this group because of a "crash" I had the other day and hope you can help me find out what happened. I was flying at a mountain and as I was flying up the mountain my drone didn't register that even though it was getting higher so was the ground and eventually I got a warning basically saying you are over 400 feet you can't go higher. so I stay at that hight for about 30 seconds then notice the drone is coming down on its own. So I start the return journey down the mountain. I get it about tree hight and 100 feet away from myself self and it basically falls out of the sky. It hit the ground hard enough to nock a prop off.

here is my flight log DJI Flight Log Viewer - PhantomHelp.com
as I start heading back down it says I got up to 900 ft in altitude. at that point, I was maybe 100 ft high and that's when it fell.

Thanks in advance for any help

 

[Mavic Mac]

Sorry to hear of the crash but welcome to the forums - great place to get tips and answers to your questions.

There are members here that are fantastic at figuring out crashes. HERE is a guide to make sure you supply the info they will need to help you.

Also, the search function is an excellent place to search for the many questions a new member will have.

 

[Thomas B]

Quick look at the logs showed an obstructed motor a few seconds before the crash.

 

[xspwhite]

Hello everyone! I joined this group because of a "crash" I had the other day and hope you can help me find out what happened. I was flying at a mountain and as I was flying up the mountain my drone didn't register that even though it was getting higher so was the ground and eventually I got a warning basically saying you are over 400 feet you can't go higher. so I stay at that hight for about 30 seconds then notice the drone is coming down on its own. So I start the return journey down the mountain. I get it about tree hight and 100 feet away from myself self and it basically falls out of the sky. It hit the ground hard enough to nock a prop off.

here is my flight log DJI Flight Log Viewer - PhantomHelp.com
as I start heading back down it says I got up to 900 ft in altitude. at that point, I was maybe 100 ft high and that's when it fell.

Thanks in advance for any help

Was it cold and wet by any chance?

 

[sar104]

The flight data don't correspond well with your description. There is no indication of the aircraft descending until you applied down throttle at 254 seconds. After that you applied multiple periods of up throttle that caused the aircraft to climb from 78 meters up to 275 meters above the home point:





However, at 376 seconds you centered the throttle and things went badly wrong:



The data indicate that the aircraft inverted and held that position for 3.5 seconds until the FC cut the motors due to the attitude excursion. That seems unphysical however, since the IMU doesn't show the aircraft as descending.



The FC also issued the following warning:

377.8,MOTOR CURRENT ERROR. CHECK YOUR PROPELLERS AND FLY WITH CAUTION.

This will require the mobile device DAT file ending FLY031.DAT to diagnose properly.

 

[PhantomFandom]

Hello everyone! I joined this group because of a "crash" I had the other day and hope you can help me find out what happened. I was flying at a mountain and as I was flying up the mountain my drone didn't register that even though it was getting higher so was the ground and eventually I got a warning basically saying you are over 400 feet you can't go higher. so I stay at that hight for about 30 seconds then notice the drone is coming down on its own. So I start the return journey down the mountain. I get it about tree hight and 100 feet away from myself self and it basically falls out of the sky. It hit the ground hard enough to nock a prop off.

here is my flight log DJI Flight Log Viewer - PhantomHelp.com
as I start heading back down it says I got up to 900 ft in altitude. at that point, I was maybe 100 ft high and that's when it fell.

Thanks in advance for any help

Good afternoon and welcome to the forum,

Sorry to hear that you has a crash with your M2Z. It is a wonderful piece of machinery.

The expert log readers will have a look and give you a better idea of what happened. However, a quick look at the log does seem to indicate a blocked or jammed prop/motor. The warning in the log comes up right before the crash.

I might respectfully suggest that you also take a great deal more time reading the manuals, watching videos, and learning more about the drone, its characteristics, and all the settings. Your question about maximum altitude problem is exactly the way the drone should behave.

The maximum altitude setting can be changed by you in the settings. The default of 400 feet is there to prevent pilots from getting in trouble. You are quite correct that you would be allowed to fly up the side of the mountain as long as the land directly below the drone is within 400 feet. However, the drone does not measure altitude directly below it. Altitude is always measured in relation to the takeoff point. So even if you were only 5 feet above ground, partway up the mountainside, if you were more than 400 feet above the takeoff point then you would have reached your maximum altitude.

 

[slup]

Yeah ... this one looks odd.

At height 120 meters the limitheight setting blocked further positive throttle inputs, but suddenly during the last positive throttle input the height skyrocketed up to 269 meter in 10sec... that's approx 14m/s from the exact figures, but the max ascend speed for the M2Z is according to spec in P-mode 4m/s. This must be wrong ... looks more like free fall, furthermore at height 237 meters the VPS sensors starts to report height again ... and that height is at 9,5meters when the log ends with a motorblocked error.

If the barometric sensor failed in the end & the AC actually went down instead of up the told story & the last positive throttle input make more sense ...

*EDIT*
Can add that Airdata indicated an ground temp forecast of 9.5F (-12.5C) during the flight ...

 

[Perspective Drones]

Quick look at the logs showed an obstructed motor a few seconds before the crash.

Thanks, for your input I believe that happened after the crash. the props were hitting the ground

 

[Perspective Drones]

Was it cold and wet by any chance?

Cold not wet

 

[Perspective Drones]

The flight data don't correspond well with your description. There is no indication of the aircraft descending until you applied down throttle at 254 seconds. After that you applied multiple periods of up throttle that caused the aircraft to climb from 78 meters up to 275 meters above the home point:

View attachment 94289

View attachment 94290

However, at 376 seconds you centered the throttle and things went badly wrong:

View attachment 94291

The data indicate that the aircraft inverted and held that position for 3.5 seconds until the FC cut the motors due to the attitude excursion. That seems unphysical however, since the IMU doesn't show the aircraft as descending.

View attachment 94293

The FC also issued the following warning:

377.8,MOTOR CURRENT ERROR. CHECK YOUR PROPELLERS AND FLY WITH CAUTION.

This will require the mobile device DAT file ending FLY031.DAT to diagnose properly.

Wow thank you for this data. At that mark you are talking about when it claimed a crazy amount I believe is when it just fell out of the sky. Also here is the file you requested

 

[Perspective Drones]

Good afternoon and welcome to the forum,

Sorry to hear that you has a crash with your M2Z. It is a wonderful piece of machinery.

The expert log readers will have a look and give you a better idea of what happened. However, a quick look at the log does seem to indicate a blocked or jammed prop/motor. The warning in the log comes up right before the crash.

I might respectfully suggest that you also take a great deal more time reading the manuals, watching videos, and learning more about the drone, its characteristics, and all the settings. Your question about maximum altitude problem is exactly the way the drone should behave.

The maximum altitude setting can be changed by you in the settings. The default of 400 feet is there to prevent pilots from getting in trouble. You are quite correct that you would be allowed to fly up the side of the mountain as long as the land directly below the drone is within 400 feet. However, the drone does not measure altitude directly below it. Altitude is always measured in relation to the takeoff point. So even if you were only 5 feet above ground, partway up the mountainside, if you were more than 400 feet above the takeoff point then you would have reached your maximum altitude.

I understand it isn't supposed to go higher than that point. That's what I set it to. But it shouldn't have started a decent on its own.

I did not know it measured altitude from the take off point. Any suggestions when flying up a mountain?
thanks

 

[sar104]

Wow thank you for this data. At that mark you are talking about when it claimed a crazy amount I believe is when it just fell out of the sky. Also here is the file you requested

Are there any other files with the same FLY031.DAT name? That only represents a couple of seconds of app logging while the aircraft was powered up.

 

[Perspective Drones]

Yeah ... this one looks odd.

At height 120 meters the limitheight setting blocked further positive throttle inputs, but suddenly during the last positive throttle input the height skyrocketed up to 269 meter in 10sec... that's approx 14m/s from the exact figures, but the max ascend speed for the M2Z is according to spec in P-mode 4m/s. This must be wrong ... looks more like free fall, furthermore at height 237 meters the VPS sensors starts to report height again ... and that height is at 9,5meters when the log ends with a motorblocked error.

If the barometric sensor failed in the end & the AC actually went down instead of up the told story & the last positive throttle input make more sense ...

*EDIT*
Can add that Airdata indicated an ground temp forecast of 9.5F (-12.5C) during the flight ...

View attachment 94333

Thank you so much for this data! Any ideas on what I should do to make sure this doesn't happen again

 

[Thomas B]

I understand it isn't supposed to go higher than that point. That's what I set it to. But it shouldn't have started a decent on its own.

I did not know it measured altitude from the take off point. Any suggestions when flying up a mountain?
thanks

If 1600’ is not enough then my solution was to land where I had LOS with my M2P, let it sit 20-30 seconds or so, and then TO again with a resetting of zero altitude and so a relative increase in max altitude.

 

[Perspective Drones]

Hello everyone! I joined this group because of a "crash" I had the other day and hope you can help me find out what happened. I was flying at a mountain and as I was flying up the mountain my drone didn't register that even though it was getting higher so was the ground and eventually I got a warning basically saying you are over 400 feet you can't go higher. so I stay at that hight for about 30 seconds then notice the drone is coming down on its own. So I start the return journey down the mountain. I get it about tree hight and 100 feet away from myself self and it basically falls out of the sky. It hit the ground hard enough to nock a prop off.

here is my flight log DJI Flight Log Viewer - PhantomHelp.com
as I start heading back down it says I got up to 900 ft in altitude. at that point, I was maybe 100 ft high and that's when it fell.

Thanks in advance for any help

Added info. If you are looking at the log. after 5 min 20 sec I can confirm the drone was descending not ascending.

 

[Perspective Drones]

Are there any other files with the same FLY031.DAT name? That only represents a couple of seconds of app logging while the aircraft was powered up.

Sorry here it is

 

[Perspective Drones]

If 1600’ is not enough then my solution was to land where I had LOS with my M2P, let it sit 20-30 seconds or so, and then TO again with a resetting of zero altitude and so a relative increase in max altitude.

Ah ok. Thanks!

 

[Thomas B]

Ah ok. Thanks!

But don’t power off anything!

 

[slup]

Are there any other files with the same FLY031.DAT name? That only represents a couple of seconds of app logging while the aircraft was powered up.

@sar104 is asking about a .DAT file here ...

Sorry here it is

... and no, this is again the same .TXT file you provided earlier.

 

[slup]

Thank you so much for this data! Any ideas on what I should do to make sure this doesn't happen again

Without the correct full sized DAT log ending with FLY031.DAT we can't say ... only speculate.