Mavic Air 2 dropped out of sky

[alexgwilliam]

Hello,

I was flying my Mavic Air early this morning and got a motor warning. I'd twice had to cancel aircraft landing which had come up randomly, and tried the return to home function. After appearing to do nothing for about 30 seconds whilst beeping at me the drone then dropped from the sky. It was still connected to the controller and I could see the lines on the road it had landed on.

I have retrieved the drone which is badly damaged.

I've crashed a fair few which have 100% been my fault but this one was very strange.

Please can someone have a look at the log and see if I did anything wrong? I don't want to be stumping up £5/600 for a repair or new drone if it was a failure from the drone.

It's only around 1 month old, no DJI refresh (I know)


Thanks in advance.

Alex

 

[alexgwilliam]

Here is the DAT file if anyone can make any sense of this at all.

 

[zeusfl]

You have a very high power consumption at the end that can indicate a motor or propeller failure.

 

[zeusfl]

The weather was fine.


super dark.

 

[alexgwilliam]

Do you feel it's the sort of thing that's worth contacting DJI about? Given the drones so new I wouldn't expect an error with the motor. Apart from the fact it was dark there was nothing particularly adverse about the conditions.

 

[zeusfl]

The weird part is that the log stop reading at 103FT altitude. Google maps does not show any hill or at least i can not identify any power like or toll pole. It may be a bird strike.

 

[spsphotos]

Speaking of dark, you did have collision lights and flying as a recreational user in class G, right?

That aside, I would think you should at least contact DJI and give them this info. If it's a malfunction of the drone they probably will cover it since it's so new. DJI Refresh is usually when the user screws up. Equipment malfunction should be covered under the warranty.

 

[zeusfl]

I guess is a hardware failure since you have few motor error prior the crash.

 

[zeusfl]

I will contact DJI and ask for warranty specially if you have Refresh kit.

 

[alexgwilliam]

Ok thank you both. I'll try my luck with DJI

 

[zeusfl]

No tall poles or trees at crash site.

 

[StantonZ]

Do you feel it's the sort of thing that's worth contacting DJI about? Given the drones so new I wouldn't expect an error with the motor. Apart from the fact it was dark there was nothing particularly adverse about the conditions.

I would. Something obviously happened @ 3'48" that could amount to a hardware failure under warranty.

 

[Lastrexking]

Speaking of dark, you did have collision lights and flying as a recreational user in class G, right?

it doesn’t apply here. OP is in the UK.

 

[A.O.]

Speaking of dark, you did have collision lights and flying as a recreational user in class G, right?

As a new guy I would love you to explain that to me. I have not yet nor do I intend to fly at night in the near future, but would be good to know. And what is class G

 

[Kilrah]

What is it with people always ignoring the warning messages?

 

[A.O.]

What is it with people always ignoring the warning messages?

So then that warning would have popped up on the viewing screen?

 

[Kilrah]

Yes.

 

[slup]

Hello,

I was flying my Mavic Air early this morning and got a motor warning. I'd twice had to cancel aircraft landing which had come up randomly, and tried the return to home function. After appearing to do nothing for about 30 seconds whilst beeping at me the drone then dropped from the sky. It was still connected to the controller and I could see the lines on the road it had landed on.

I have retrieved the drone which is badly damaged.

I've crashed a fair few which have 100% been my fault but this one was very strange.

Please can someone have a look at the log and see if I did anything wrong? I don't want to be stumping up £5/600 for a repair or new drone if it was a failure from the drone.

It's only around 1 month old, no DJI refresh (I know)


Thanks in advance.

Alex

The reason for this is most probably a seizing left front motor ... already at 137sec into the flight the AC wanted to force land but you cancelled it ... then again at 175sec ... & again at 199sec, but you aborted & continued to fly. This was early warning signs ...

This was the message out from the DAT log event stream at the first force landing ... no apparent reason is given there unfortunately.


Then at 243sec the current to that left front motor started to go high ... something makes it hard to turn, see yellow graph.

(Click on the charts to make them larger)


At 280sec the flight controller orders full command to the left front to have it keep up the rpm's as needed, see purple graph.



At 286sec it's game over & the left front motor seizes & drops the rpm, see purple graph... a couple seconds later the FC orders motor shut down as seen from the DAT log event stream further below ...



Here the DAT log event stream that explains why all motors stops ...



Hard to say anything about the reason for this ... but you mentioned that you have crashed earlier so a bent motor shaft? Or debris going into the motor at start or earlier landings ... or manufacturing fault?

Contact DJI to get their point of view on this...

 

[slup]

The weird part is that the log stop reading at 103FT altitude. Google maps does not show any hill or at least i can not identify any power like or toll pole. It may be a bird strike.

View attachment 118810

In this case not weird at all ... the FC force stopped the motors mid flight & as you only are looking at the TXT log which only records during motors on it will look like that. The TXT records until 286sec but the DAT a tad over 288sec, there the AC hits the ground & power cuts or the AC loses connection with the RC... ending the DAT log, last reading from the ultrasonic sensor is 0,26m above ground.

 

[spsphotos]

As a new guy I would love you to explain that to me. I have not yet nor do I intend to fly at night in the near future, but would be good to know. And what is class G

Class G airspace is uncontrolled airspace. There are two primary types, controlled (A,B,C,D, and E) and uncontrolled, G. In Class G, you can pretty much fly anywhere (with certain rules, like 400ft AGL, VLOS, etc). You don't need anyone's permission to fly. G makes up the majority of the airspace in the U.S. A,B,C,D,and E deal with controlled space around airports, etc. There are other types like restricted (think Military bases, federal, etc). There are other areas as well, for example, you can't fly in a national park. As a hobbyist, you can fly at night in Class G airspace but you need to have some type of collision light on the drone (Check out Firehouse Technologies) that can be seen from at least 3 miles away. As a Part 107 licensed pilot though, you can't fly at night without a waiver (yes, I know...seems backwards....but that's what it is). You can fly in controlled airspace (with FAA approvals) 30mins before sunrise and 30 mins after sunset (civil twilght), but you still need that light.

Check out Pilot Institute. They have some free basic courses on various drones and general rules, etc. And an EXCELLENT Part 107 exam prep course (not free).