Phantom 4 Pro v2 crashed today in Iceland

RPP

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The motors shut down mid-flight due to the following:

250.7: ESC_StallNearGround

Still looking to see what caused that. The mobile device DAT file ending FLY233.DAT would be helpful.


Attached is the DAT file. (Where can I convert it myself for viewing?)
 

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  • 2020-01-30_11-55-31_FLY231.DAT
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JeffreyS

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Too bad there was not more snow on the ground. I'll bet 18" or more would have cushioned the impact.
 
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24 - degrees is not really all that cold. Even though your handbook says 32 and above. I'm guessing that your battery dropped. Did you warm it before take off, or was it sitting in the cold?
 

RodPad

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24 - degrees is not really all that cold. Even though your handbook says 32 and above. I'm guessing that your battery dropped. Did you warm it before take off, or was it sitting in the cold?
Did you look a the log?

Rod
 

sar104

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The log dosen't really say much that I could read on my phone. But I did see an error about a motor obstruction, but what would cause that?

I suspect that was caused by the cold and foggy conditions, although I haven't had a chance to examine the DAT file yet. It was also likely the precursor to the ESC stall state that subsequently caused the FC to shut down the motors.
 
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I suspect that was caused by the cold and foggy conditions, although I haven't had a chance to examine the DAT file yet. It was also likely the precursor to the ESC stall state that subsequently caused the FC to shut down the motors.
Hmmm..
 

sar104

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Interesting - FLY232.DAT contained the flight data, even though the txt log indicated a file index of 233. Anyway - this was an icing event. If you look at the motor current during the flight you can see that it rises with time to keep the prop speed constant as the drag on the props increases.

motors.png


This is the typical signature of icing. Eventually the drag becomes too large, and the motor obstructed messages appear, and then finally ESC stall and motor shutdown:

264.604 : 16950 [L-RC]craft ctrl failed!!!
265.539 : 16995 [L-FMU/MOTOR]motor is continued stall
265.540 : 16995 [L-FMU/MOTOR] Stop. reason:motor stall near ground
265.540 : 16995 [L-FMU/MOTOR]Total start times: 2, time: 250.70
265.540 : 16995 [L-PWM]set actuator mode:IDLE
265.540 : 16995 [L-N_MIS]req abort all for motor stopped
265.543 : 16995 [L-FMU/FSM]state changed. cur: motor off

That's simply a hazard of flying in those conditions, and why DJI doesn't recommend it.
 
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RPP

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Interesting - FLY232.DAT contained the flight data, even though the txt log indicated a file index of 233. Anyway - this was an icing event. If you look at the motor current during the flight you can see that it rises with time to keep the prop speed constant as the drag on the props increases.

View attachment 117077

This is the typical signature of icing. Eventually the drag becomes too large, and the motor obstructed messages appear, and then finally ESC stall and motor shutdown:

264.604 : 16950 [L-RC]craft ctrl failed!!!
265.539 : 16995 [L-FMU/MOTOR]motor is continued stall
265.540 : 16995 [L-FMU/MOTOR] Stop. reason:motor stall near ground
265.540 : 16995 [L-FMU/MOTOR]Total start times: 2, time: 250.70
265.540 : 16995 [L-PWM]set actuator mode:IDLE
265.540 : 16995 [L-N_MIS]req abort all for motor stopped
265.543 : 16995 [L-FMU/FSM]state changed. cur: motor off

That's simply a hazard of flying in those conditions, and why DJI doesn't recommend it.

Thank you for the analysis.
 
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Yup, icing of the props. I had similar icing with my Air the other day. Likely as the ice accumulated the lift created decreased causing the motor to spin faster to maintain position... or drag was the cause.

Eventually the ESC got spooked with the anomalous RPM and odd movements and shut it down.

Sorry to hear. Would have been fine without the fog I estimate.
 

sar104

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Yup, icing of the props. I had similar icing with my Air the other day. Likely as the ice accumulated the lift created decreased causing the motor to spin faster to maintain position... or drag was the cause.

Eventually the ESC got spooked with the anomalous RPM and odd movements and shut it down.

Sorry to hear. Would have been fine without the fog I estimate.

As you can clearly see in post #34, it was drag, not increased motor speed, that caused the problems.
 
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Icy conditions in Iceland. Also, IMO.. I think that freezing cold weather can make the plastics of your aircraft very brittle. Just like metal, plastic can shirnk and expand with changing temperatures.

There is something that can be said about a metal moter mounted to plastic parts as well. since They both can react to temperatures in different ways.

Just a thought.

Im sure heat can have different effects too.
 

PhantomWetSuits

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when you got to the drone did you see that the Props were frozen , or any sign of that ?

Im asking because I have not had any crashes yet in any of the ice storms I have flown in and I have also flown with props that were torn apart.

I recently just flew in 5 below zero over the lake getting splashed with water and still could not get the drone to crash.

Curious on your own thoughts.
I can see blocked motors being the cause but not so much the icing on the props.

Phantomrain.org
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