Mayday - MAVIC Crash Investigation

taus · Apr 9, 2017

After calibrating, updating firmware and charging everything, I took my brand new Mavic Pro out for a couple of test flights. Two flight of 2-3 minutes each went fine, but on the third flight it just crashed without warning.

This is the flight log:
Airdata UAV - Flight Data Analysis for Drones

And here is a video:

It was a day with some wind but I think anyone watching the video will say that the wind was acceptable. Look at the flags 30 seconds into the video. Also note that the video just stops. None of the crash was recorded and battery power was fine. Last warning in the app was "week signal..." (=no signal in this case). If I had hit something or the wind was too strong, I think it would be on the video recording?

It looks a lot like a power failure. I think this has to be a manufacturing defect. Do you agree?

Cyberpower678 · Apr 9, 2017

Your average wind speed was SE at 15.6 km/h with a high gust of 22.2 km/h during that flight.

It looks like the battery disengaged from the drone. Was it in the drone when you found it?

taus · Apr 9, 2017

Cyberpower678 said:
Your average wind speed was SE at 15.6 km/h with a high gust of 22.2 km/h during that flight.

It looks like the battery disengaged from the drone. Was it in the drone when you found it?

Yes, the battery was in the drone when I found it.

taus · Apr 9, 2017

I had two flights prior to this flight with the same battery and the drone looks to be rather stable when the video stops. So I really find it hard to believe that the battery popped out and back in by itself.

I will do some tests to see if it is realistic that the battery can power the drone without being locked into place. Thanks for the comment!

taus · Apr 9, 2017

It is possible to power on the drone with the battery only locked in place in one side. It is tricky to do so and much easier to get it to turn on with both sides locked.

Since the drone had done two complete flights with the same battery and was found with the battery in place, I think it is unlikely.

(and I think it should have been designed not to fly without both sides locked)

sekine12 · Apr 22, 2017

taus said:
It is possible to power on the drone with the battery only locked in place in one side. It is tricky to do so and much easier to get it to turn on with both sides locked.

Since the drone had done two complete flights with the same battery and was found with the battery in place, I think it is unlikely.

(and I think it should have been designed not to fly without both sides locked)

I agree, it shouldn't fly without both sides locked. But, it's good that the electrical contacts are solidly engaged by the time that the locks engage.

The Mavic seems to be very aerodynamically stable in free-fall, usually landing belly down. If the battery disengaged and then belly-flopped there's a really good chance it'd get slammed back into place.

flyNfrank · Apr 22, 2017

Cyberpower678 said:
Your average wind speed was SE at 15.6 km/h with a high gust of 22.2 km/h during that flight.

It looks like the battery disengaged from the drone. Was it in the drone when you found it?

Due to battery type, DJI designs their aircraft to disengage the battery upon impact.

flyNfrank · Apr 22, 2017

For a much better crash analysis, read instructions from page on how to upload the .TXT file from the device used.

https://www.phantomhelp.com/LogViewer/Upload/

Threshold · Apr 22, 2017

Only thing I could tell from the video was that you were possibly in sport mode because of the blades being visible. But other members should be able to help with the flight log info

dewster · Apr 23, 2017

Maybe Sport Mode is too much for the battery in certain flight conditions. I'd like to know if the craft will shut off if dogged in sport mode. Maybe there should be a tachometer to warn if you are approaching the redline during flight.

sekine12 · Apr 23, 2017

dewster said:
Maybe Sport Mode is too much for the battery in certain flight conditions. I'd like to know if the craft will shut off if dogged in sport mode. Maybe there should be a tachometer to warn if you are approaching the redline during flight.

There was another thread here about a guy flying flat out in sport mode for a while and he got a battery overheat warning, so that's not it.

Marco Cantieni · Apr 23, 2017

I avoid flying in sports mode full throttle for longer than 30seconds while I'm recording. I simply don't want to risk a battery failure and I also want my batteries last a few month.

Robbyg · Apr 23, 2017

Upload the DAT file from the Mavic and we can see if it is a power failure.

Use DJI Assistant 2 and download the Flight Record files then upload them to a file sharing service like Dropbox.

Rob