Really perplexing and frustrating:
http://healthydrones.com/main?share=wFsHjn

Minimal wind:
http://yellowstoneclub.com/weather/

My Mavic crashed within 30 seconds of takeoff.  As soon as it lifted off it started moving in a wide circle at up to 8 m/s, with minimal control input from me.  Did not hover in place at all.

Happened once before when I was testing at home but I was able to grab the drone with my hand and remove the battery before anything happened.  Not so lucky today.  It ran off, I tried to control it but nothing worked.  I tried to swipe to land and it crashed on a hill.  The drone was moving so quickly I lost visual contact in just a few seconds!

Any idea what went wrong?  Looking at the log the compass data seems weird, but it never asked me to calibrate the compass.

Three sets of propellers broke, and I found that the gimbal base plate was dislodged and protruding out from the tab that keeps it in place.  Manually slid it back into place, but I get camera sensor error and aircraft motor obstructed errors.  The gimbal itself keeps restarting and trying to initialize, but I think the range of motion is reduced and so it keeps restarting.

Any ideas what to do?  Recalibrate or send in for repairs?

Thanks

Sounds like a classic case of compass error - when did you last calibrate it ?

Chriscycling Posted at 2017-2-5 04:34
Sounds like a classic case of compass error - when did you last calibrate it ?

Calibrated the compass just recently; the app didn't ask me to calibrate at all.  
I was flying in beginner mode too, it ran off more than 100ft away almost immediately.

The compass errors in the logs don't show up until shortly before the crash.  What causes the compass to need recalibration?

Any ideas on how to fix the camera/gimbal?

The best way to analyse your flight is to have a look at the replay of your flight. MAybe you can record the flight replay and make it available here?

Instructions how to do this can be found at Guide: how to report a flight problem.

Grimani Posted at 2017-2-5 04:37
Calibrated the compass just recently; the app didn't ask me to calibrate at all.  
I was flying in beginner mode too, it ran off more than 100ft away almost immediately.

I'd re calibrate everything in the following order and restart after every one

1)) IMU
2) Compass - make sure you do it outside and in an open area
3) Remote
4) Gimbal
A bad compass calibration can be worse than none at all. Always do it in an open area, leave your phone well away from the drone to minimise interference.

Couple of other questions

What device are you using ?
What version of the App are you using ?

Dronoob Posted at 2017-2-5 04:39
The best way to analyse your flight is to have a look at the replay of your flight. MAybe you can record the flight replay and make it available here?

Instructions how to do this can be found at Guide: how to report a flight problem.

Grimani Posted at 2017-2-5 04:44
https://www.youtube.com/watch?v=q8_ztH-0oQg&feature=youtu.be

Just seen this - looks like the homepoint was not the homepoint and it shows a signal loss so RTH was triggered. Were you flying in wi-fi mode ?

Chriscycling Posted at 2017-2-5 04:47
Just seen this - looks like the homepoint was not the homepoint and it shows a signal loss so RTH was triggered. Were you flying in wi-fi mode ?

No, I was flying with my controller with iphone attached.  I think the RTH was triggered by me as soon as I realized it was out of control.  It started the arc as soon as it took off, so a few seconds into the flight I tried to force it to land.

In any case it was flying away from the homepoint so I'm not sure RTH caused the issue?

Grimani Posted at 2017-2-5 04:44
https://www.youtube.com/watch?v=q8_ztH-0oQg&feature=youtu.be

The top bar should show the current flight mode. Can you record the video without that AceThinker banner on top?

Hi grimani sorry to hear you crashed, looking at those logs obviously very short 30 sec flight doesn't tell a lot, a couple of things. You had very weak gps signal , 5/6 sats, this could have caused aircraft to go into Atti mode causing it to drift on the wind, so wouldn't need much movement on the sticks for it to head left as you said, all your gps signal is in the red.
You were in beginner mode and had reached your limit don't know if you pushed RTH or aircraft went in to RTH as a precaution.
It is also reporting bad radio signal asking you to properly set antenna, your signal was blocked at this point, and this could also be responsible for RTH .
What do you have your RTH set at, why did you do compass calibration and where this is important, so many things could have gone wrong, but for me looking at this and knowing your a new flyer, this may be down to experience,
But for you it's important you find out what happened, we all learn a lot more from our mistakes.

Just one tip I can give you, you were flying very low with minimal signal , you said you had a similar issue previously so there may be a problem with gps signal where your flying from. If you have bad gps signal just raise your height and it should improve.

I hope damage wasn't to bad and you can recover soon, Good luck..

Dronoob Posted at 2017-2-5 04:59
The top bar should show the current flight mode. Can you record the video without that AceThinker banner on top?

It's in beginner mode until flight distance of 100m, and then GoHome mode until 126m, then it crashes and goes into ATTI mode.

I will upload a new video later, am waiting for the Ace Thinker license key (just bought it).

should be an easy case, because the flight it so short, upload your flight data and we will take a look.

Grimani Posted at 2017-2-5 04:44
https://www.youtube.com/watch?v=q8_ztH-0oQg&feature=youtu.be

Grimacini, did you takeoff from a concrete structure? I can't tell from the video if you were on the ground or the larger structure. I ask because this does look like a possible compass issue as mentioned earlier.

Drew77 Posted at 2017-2-5 05:20
should be an easy case, because the flight it so short, upload your flight data and we will take a look.

I've already uploaded above - do you need more data?   Thanks

Daroga Posted at 2017-2-5 05:36
Grimacini, did you takeoff from a concrete structure? I can't tell from the video if you were on the ground or the larger structure. I ask because this does look like a possible compass issue as mentioned earlier.

No, I took off from the ground (concrete sidewalk on ground floor of a builiding.  The ground slopes upwards on going to the left hand side, but is flat where I took off.

hallmark007 Posted at 2017-2-5 05:01
Hi grimani sorry to hear you crashed, looking at those logs obviously very short 30 sec flight doesn't tell a lot, a couple of things. You had very weak gps signal , 5/6 sats, this could have caused aircraft to go into Atti mode causing it to drift on the wind, so wouldn't need much movement on the sticks for it to head left as you said, all your gps signal is in the red.
You were in beginner mode and had reached your limit don't know if you pushed RTH or aircraft went in to RTH as a precaution.
It is also reporting bad radio signal asking you to properly set antenna, your signal was blocked at this point, and this could also be responsible for RTH .

I didn't do compass calibration before this flight because the app didn't ask for it (and the manual says only to do calibration when requested)

I pushed RTH after the aircraft went out of beginner range and was clearly malfunctioning.  Could bad radio signal cause this?  Keep in mind that after RTH mode was activated it still continued moving in an arc away from me.

Chriscycling Posted at 2017-2-5 04:42
I'd re calibrate everything in the following order and restart after every one

1)) IMU

I'm using the Mavic Pro, with remote control and the newest version of the DJI GO app on Iphone 7

Grimani Posted at 2017-2-5 05:41
I've already uploaded above - do you need more data?   Thanks

I think what Drew77 is suggesting is that you upload the Mavic's .dat files, using the DJI Assistant software. There's a a lot more data in them than what the RC shows in the flight playback.

Grimani Posted at 2017-2-5 05:46
I didn't do compass calibration before this flight because the app didn't ask for it (and the manual says only to do calibration when requested)

I pushed RTH after the aircraft went out of beginner range and was clearly malfunctioning.  Could bad radio signal cause this?  Keep in mind that after RTH mode was activated it still continued moving in an arc away from me.

At H went into go home mode

At J went back to beginner mode did you cancel go home.

As others said play your flight back in the dji app or upload here.

Jason Lane Posted at 2017-2-5 05:50
I think what Drew77 is suggesting is that you upload the Mavic's .dat files, using the DJI Assistant software. There's a a lot more data in them than what the RC shows in the flight playback.

How do I upload the dat file to the forum?  I've downloaded it to my computer

hallmark007 Posted at 2017-2-5 05:53
At H went into go home mode

At J went back to beginner mode did you cancel go home.

No I did not cancel go home.  I think it went back to beginner mode when it hit something.

Grimani Posted at 2017-2-5 05:42
No, I took off from the ground (concrete sidewalk on ground floor of a builiding.  The ground slopes upwards on going to the left hand side, but is flat where I took off.

Concrete sidewalks contain rebar, which can affect your compass.

Grimani Posted at 2017-2-5 05:57
No I did not cancel go home.  I think it went back to beginner mode when it hit something.

It says beginner mode at 268ft, so maybe not .

hallmark007 Posted at 2017-2-5 06:02
It says beginner mode at 268ft, so maybe not .

Yes, I checked again and it didn't move any more after 268ft.  It had hit something then changed to beginner mode.

I think the real issue is that it started moving away from me on takeoff and continued to accelerate from 10mph all the way to 30mph without any controls from me, and despite being in beginner mode where it shouldn't move more than 100ft from me!

http://www.phantomhelp.com/LogViewer/TX9JPQH5O939OG2W95QN/

Chriscycling Posted at 2017-2-5 04:42
I'd re calibrate everything in the following order and restart after every one

1)) IMU

It keeps failing on gimbal calibration.  Gimbal obstructed.  It moves, but not the full range (can't do the full 90 degrees down and 30 degress up, only about 50 degrees depending on whether it starts looking down or ahead).

Is this just something that needs to be repaired as a physical hardware issue?

It isn't seems like compass issue to me. Compass readings was good till the last few seconds of flight.
Looks like these quick rotations were caused by hitting to some obstacle (there was only about 5-7 meters height at that moment).

I not sure if this was caused by weak GPS signal. If the flight path that is shown on HealthyDrones is just the same as it really was, then obviously, there was no problem with GPS positioning too.

Grimani Posted at 2017-2-5 05:57
No I did not cancel go home.  I think it went back to beginner mode when it hit something.

Concurring with Hallmark007, it looks like you tookoff from the sidewalk without or borderline GPS. Rebar iron in the sidewalk skewed the compass and caused the circular arc. GPS coverage decreased and compass went from bad to worse. RTH initiated with unstable sensors and no GPS = crash. The toiletbowl effect (flying in a large increasing arc) is typical of compass problems. Why the Mavic allowed you to even start the motors is the question. The Go 4 App should have seen the parameters and prohibited the launch. You were using GO4 and not the GO app, correct?

Grimani Posted at 2017-2-5 05:57
How do I upload the dat file to the forum?  I've downloaded it to my computer

Put it into dropbox:
https://www.dropbox.com/s/5ojj8m ... 5_07-45-29.DAT?dl=0

Daroga Posted at 2017-2-5 06:12
Concurring with Hallmark007, it looks like you tookoff from the sidewalk without or borderline GPS. Rebar iron in the sidewalk skewed the compass and caused the circular arc. GPS coverage decreased and compass went from bad to worse. RTH initiated with unstable sensors and no GPS = crash. The toiletbowl effect (flying in a large increasing arc) is typical of compass problems. Why the Mavic allowed you to even start the motors is the question. The Go 4 App should have seen the parameters and prohibited the launch. You were using GO4 and not the GO app, correct?

Ugh, It was DJI GO - not GO 4.  Didn't even realize there was a GO 4...why do they make two versions of the same thing if one is going to cause issues?

Sorry for your loss (I also had loss last year with my P3A for unknown reasons) . It does look like a compass and/or App issue. Also for future it's best to take off with a full battery especially when it's cold outside.  

Grimani Posted at 2017-2-5 06:17
Ugh, It was DJI GO - not GO 4.  Didn't even realize there was a GO 4...why do they make two versions of the same thing if one is going to cause issues?

Don't know that GO App is a problem. It should have alerted you like this:

This is an Android mobile device, haven't tried with iOS for the same message. This could be a combination of sensor problems and beginner mode.
I know that GO4 will not start motors if there are compass problems.....
You're going to have to send it back to DJI Support and let them take a look. We may all benefit from your tragic misfortune....

Daroga Posted at 2017-2-5 06:52
Don't know that GO App is a problem. It should have alerted you like this:
[view_image]
This is an Android mobile device, haven't tried with iOS for the same message. This could be a combination of sensor problems and beginner mode.

Gimbal issues:



Sorry for the noise, I think it might be the EMF from the Mavic affecting the microphone on my iphone that recorded the video

I haven't gotten any response from DJI support.  What's the best way to send my drone back to them?  (I'm in Hong Kong)
Don't think I got that message in DJI GO, weird.  There was definitely no mention of any compass issues or need for recalibration in the DJI GO app (I had gotten the recalibration message before).

From a piloting perspective, when you see this behavior, with the Mavic and auto ATTI mode, you have a least two choices:

1) recognize immediately as an uncontrolled flight emergency situation and try to put it back on the ground. Since it's likely partially uncontrollable you can apply counter controls but try to get it on the ground as soon as possible. Don't try to fly i back home. Get it on the ground. It will likely flip due to the lateral velocity but the sooner it lands the less damage...

2) If possible, climb to try to gain clear line of site to more GPS satellites and get out of ATTI mode. This is likewise a 50-50 coin toss. If you recover, great. If not, them climbing will just create a fly-away.

As pilot in command, the choices are yours. Always be prepared for the unexpected and always try to fly safely...

Grimani Posted at 2017-2-5 06:05
Yes, I checked again and it didn't move any more after 268ft.  It had hit something then changed to beginner mode.

I think the real issue is that it started moving away from me on takeoff and continued to accelerate from 10mph all the way to 30mph without any controls from me, and despite being in beginner mode where it shouldn't move more than 100ft from me!

At 17.6 going home you almost immediately lost gps and back to beginners mode in Atti, aircraft will move on the wind.

Also it looks like take off was ok then you seem to fly over a building does it have some sort of metal roof, also it looks like there were some sort of power lines or metal structures in the area ,although it's hard to see in the sat picture , did you happen to hit a power line or where you flying dangerously close to them.
If there were power lines close by or meta structures or that roof was metal all of these will have an effect on your compass,

Were you in sports mode?

hallmark007 Posted at 2017-2-5 07:05
At 17.6 going home you almost immediately lost gps and back to beginners mode in Atti, aircraft will move on the wind.

Also it looks like take off was ok then you seem to fly over a building does it have some sort of metal roof, also it looks like there were some sort of power lines or metal structures in the area ,although it's hard to see in the sat picture , did you happen to hit a power line or where you flying dangerously close to them.

I was not in sports mode.  The log shows ATTI mode after 19s which is after it had already crashed I think.

I took off from a sidewalk in front of a building, the area was pretty clear.  I didn't fly over a building but was outside of it.  The drone started moving uncontrollably immediately after takeoff.  The 3 times I used the controls at 8s, 11s, and 12s was to try and counteract the drifting and of course it didn't work.  I then tried RTH, but I guess I should have tried to land it immediately.  

How sensitive is the Mavic to metal?  Do I need to be 1m away?  10m away?  It seems pretty ridiculous if sensitivity is so high so as to be unflyable in all but the most remote of locations.

Daroga Posted at 2017-2-5 07:05
From a piloting perspective, when you see this behavior, with the Mavic and auto ATTI mode, you have a least two choices:

1) recognize immediately as an uncontrolled flight emergency situation and try to put it back on the ground. Since it's likely partially uncontrollable you can apply counter controls but try to get it on the ground as soon as possible. Don't try to fly i back home. Get it on the ground. It will likely flip due to the lateral velocity but the sooner it lands the less damage...

Good advice - I chose 1 but unfortunately hit RTH instead of land immediately.  Actually, how do I force an immediate landing even if the sensors think there are obstacles etc?

2 I thought had real risk of a fly-away since I had no controls other than altitude (I think) and had no idea what the issue was at that time.

Grimani Posted at 2017-2-5 07:18
I was not in sports mode.  The log shows ATTI mode after 19s which is after it had already crashed I think.

I took off from a sidewalk in front of a building, the area was pretty clear.  I didn't fly over a building but was outside of it.  The drone started moving uncontrollably immediately after takeoff.  The 3 times I used the controls at 8s, 11s, and 12s was to try and counteract the drifting and of course it didn't work.  I then tried RTH, but I guess I should have tried to land it immediately.  

Compass is sensitive to metal or anything magnetic, looking at satellite picture it shows aircraft flying over the building, also where there power lines in the area.
If you crashed at 19 sec then you where 24ft in the air, so my question is what did you hit.

Grimani Posted at 2017-2-5 07:18
I was not in sports mode.  The log shows ATTI mode after 19s which is after it had already crashed I think.

I took off from a sidewalk in front of a building, the area was pretty clear.  I didn't fly over a building but was outside of it.  The drone started moving uncontrollably immediately after takeoff.  The 3 times I used the controls at 8s, 11s, and 12s was to try and counteract the drifting and of course it didn't work.  I then tried RTH, but I guess I should have tried to land it immediately.  

http://www.phantomhelp.com/LogViewer/TX9JPQH5O939OG2W95QN/


If you check out the picture you will see the path of your flight and what looks like power lines.

I hate to say it and I'm no expert by any means, but from my opinion the flight seemed rushed as the users did not fully read the manual and did not have a good idea about the drone (just my opinion don't freak out) even tho these are much easier to fly compaired to the old drones you still have to go through a check list ( just like with a real aircraft) before you take off

Just like you say in your original post this happens before at your house and you were able to catch it, that should of set of a big red flag to take a step back and do some flight analysis and do some reading, this is an expensive unit it's not worth to rush into it and cause a crash (unless you have a lot of money and don't care) now you most likely have to send it to DJI and that is a very lengthy process, hope it works out for you