HI folks,

So I just updated my Mavic firmware to the following:

App: 4.1.17
Aircraft: 01.04.0000
Basic apply safe database: 01.00.01.05
Precise App Fly database 01.00.01.07

So I start up the Amvic and controls the usual way. I get a message of  conflicted firmware and asks me to update. I do this and it says all  good to go.

I start motors by pushing controls inwards to toward me and I hear the  audible 'take off' message and I push up on the left control (altitude)  the same way I always do. The drone llifts off the deck about 20cm and  then the motors just stop and the drone hits the deck again.

I have never had this happen to me before. I have always had great  confidence in the equipment and I have used it in some places that made  me nervous but I never worried about the aircraft doing anything like  this. I work at sea and was using it on a moving vessel, which I have  done before without incident. Now I have lost all confidence. Had it  done this 60 seconds later it would now be sinking to the bottom of the  ocean.

Anyway know what's going on? I'm terrified to use it now which sucks  because I'm crossing the Atlantic and you don't get many chances to  fillm like this.

I made a short video of the data on my phone which shows the inputs I made during the 00.07 second flight

https://www.flickr.com/gp/152247082@N04/6ToE9G

https://flic.kr/p/ZtcvTm

https://flic.kr/p/21ymZ2a

Was the battery firmly locked in place? If so, then you probably have a defective Mavic and the best tool for diagnosing what happened is the flight log (DAT file) stored on the Mavic itself. The instructions for retrieving DAT files are here, and once you've download the information you'll need to upload it to DropBox (or a similar service) and provide a link to it in this thread. The correct file should have a date and time that correspond to when the flight occurred and will be at least tens of megabytes in size, though if you aren't sure which is the correct one then feel free to include any that might be relevant.

Ouch, hopefully not much damage. After the crash did you restart the Mavic.

Did you tun off and back on the MP after the FW update. Did you put in a new battery after the FW update, before your short flight. Did you verify all you GO4 setups before flying.

Locoman Posted at 2017-11-15 07:23
Did you tun off and back on the MP after the FW update. Did you put in a new battery after the FW update, before your short flight. Did you verify all you GO4 setups before flying.

Hi,

It didn't get high enough to sustain any damage.

I didn't do any of those things you mentioned as I wasn't aware I was supposed to. I don't know what GO4 setups is.

Woe Posted at 2017-11-15 05:17
Ouch, hopefully not much damage. After the crash did you restart the Mavic.

I did and I flew it indoors and it seemed t lift off ok, but now I'm worried about using outside and taking any 'risks' now until I know what caused it.

Just wanted to add that the movement you see in the video is the ship moving not the Mavic flying. The flight only lasts from when you see the upward input on the controller.

Weirdly it says no data!


https://flic.kr/p/21yLZkt

eSysman Posted at 2017-11-15 09:08
Weirdly it says no data!

[view_image]

Try the "Flight Data" tab.

BudWalker Posted at 2017-11-15 09:21
Try the "Flight Data" tab.

It opens an app and then the instructions you posted said I should see the available DAT files, but there is non.
Actually it says the SD card should mount and I can navigate to it and access the files but it's not mounted.

How can it be there is no flight logs? Does it reset after a firmware update?

eSysman Posted at 2017-11-15 09:52
It opens an app and then the instructions you posted said I should see the available DAT files, but there is non.
Actually it says the SD card should mount and I can navigate to it and access the files but it's not mounted.

I see now that you're using a Mac. I've not experienced this, thankfully, since I don't have a Mac. But, I've heard there can be difficulties in seeing the mounted drive. Maybe someone who has a Mac can help you.

BudWalker Posted at 2017-11-15 11:04
I see now that you're using a Mac. I've not experienced this, thankfully, since I don't have a Mac. But, I've heard there can be difficulties in seeing the mounted drive. Maybe someone who has a Mac can help you.

I have a PC as well if that's an issue I'll try that

Had you reported this case to our support? If you haven't please sync your flight record to the cloud, PM me your account, and also help to export the data from the RC, and if you can access the data from the drone finally  (note that you need to use the latest Assistant 2 v1.1.6), please also provide it to me. Please upload the data to Dropbox so I can catch it. If you have reported it to our support, please PM me with the ticket number. Also, you can contact support.nl@dji.com directly. Thanks.

You said you were on a boat and only lifted off about 20cm. I am just wondering if the movement of the boat caused the Mavic to think it had landed again and stopped the motors. It might be something to do with the IMU but this is a really tricky one. Would you normally stop at such a low height or have you previously taken off to a greater height while at sea?

On your DJI GO 4 app click the 3 dots at the top right corner and find battery (With the mavic powered on). Check to see if there's no critical differences than usual.

On your DJI GO 4 app click the 3 dots at the top right corner and find battery (With the mavic powered on). Check to see if there's no critical differences than usual.

Jenee 2 Posted at 2017-11-15 21:01
You said you were on a boat and only lifted off about 20cm. I am just wondering if the movement of the boat caused the Mavic to think it had landed again and stopped the motors. It might be something to do with the IMU but this is a really tricky one. Would you normally stop at such a low height or have you previously taken off to a greater height while at sea?

It's possible, but the ship was moving very slowly (6knots) and was not moving up and down (pitching). Usually at sea I shoot vertically up to clear the railings otherwise it would hit them as the ship moves. This is what I attempted.

DJI Thor Posted at 2017-11-15 20:23
Had you reported this case to our support? If you haven't please sync your flight record to the cloud, PM me your account, and also help to export the data from the RC, and if you can access the data from the drone finally  (note that you need to use the latest Assistant 2 v1.1.6), please also provide it to me. Please upload the data to Dropbox so I can catch it. If you have reported it to our support, please PM me with the ticket number. Also, you can contact support.nl@dji.com directly. Thanks. https://www.youtube.com/watch?v= ... xD4Dm-tX4cnvzX&t=3s

I sent you the files.

So I have an update. It turns out another crew member has the same drone. He tried to fly his today in calm conditions and the exact same thing happened. He tried 4 times and it happened the same each time, in one incident it flipped on it's head (inverted). I have video, I'm uploading to YouTube right now. Once it's uploaded I'll post the link.

He updated to the same firmware so the issue might be in there. I have launched from moving vessels before so there is something different.

OK here is video

Thats not good! Too serious to mess around with FW refresh etc - the only real solution to this is to follow DJI Thor' instructions and send it back to DJI asap. I personally would never fly any drone that cuts the motors - image if this happened 400' up - not worth the risk...

A CW Posted at 2017-11-17 09:15
Thats not good! Too serious to mess around with FW refresh etc - the only real solution to this is to follow DJI Thor' instructions and send it back to DJI asap. I personally would never fly any drone that cuts the motors - image if this happened 400' up - not worth the risk...

This is another drone, not mine!

I have sent the DAT file to someone at DJI

eSysman Posted at 2017-11-17 10:24
This is another drone, not mine!

I have sent the DAT file to someone at DJI

I see. Good luck on getting the return back in perfect working order - you did the right thing.

eSysman Posted at 2017-11-17 08:53
OK here is video

https://youtu.be/wpbBxC2ETlw

You say you were moving at abt 6 kts. And from the video,  I can see the drone moving backwards after lifting off.   I'm guessing that  it's trying to hover over what it thinks is a stationary floor, but the GPS location is changing.  Maybe the flight control system is getting confused  by conflicting inputs and just shuts down.

You might try turning off VPS.  

Have you tried hand launching?

eSysman Posted at 2017-11-17 10:24
I have sent the DAT file to someone at DJI

So, apparently, you were able to extract the .DAT? If you could Dropbox it and provide the link we could look at it. This seems like it might be an interesting incident.

eSysman Posted at 2017-11-17 10:24
This is another drone, not mine!

I have sent the DAT file to someone at DJI

You can actually see the deck moving a bit in that video. I still think it may have something to do with the IMU trying to do its initial calibrations on the moving deck. What was the version of the last firmware update that worked? And I assume your friend also recently updated his firmware.
Normally you would want the Mavic to stay still when starting up until the IMU self check has been done.

eSysman Posted at 2017-11-17 08:08
I sent you the files.

Sorry for the late reply, how about the flight records? Had you uploaded them to the cloud? Please also PM me your DJI account so I can access it.