Mavic Went CRAZY!... CRASHED

Toyotamdt · Apr 12, 2018

Took off for a short flight, got about a few hundred feet away, maybe 75' altitude. All of a sudden the thing went crazy, wasn't flying level and seemed to be flying at a speed similar to sport mode. It somehow headed back in my direction flying on it's side (life knife edge) and slammed into a storage container in the parking lot at work.

I started a case with DJI and will ship it to them tomorrow. I've only had it for a few weeks, I'm almost in tears.

Any thoughts?

I completely let go of the controls when it was doing this and NOTHING!

genesimmons · Apr 12, 2018

could have been crazy interfiernece from all the metal, theres one spot i have flown from and i get a interfernce warning and my bird did some weird things with no stick movement from me, i dont fly there any more as its happend 2 times same thing, i bet it was interernce and affected your compass and it didnt know where it was going

Toyotamdt · Apr 12, 2018

I got some compass warning... I've flow here a bunch without issue. Crazy.

MavicCF · Apr 12, 2018

Could you post your flight logs? Here is a link to where you can upload them.

msinger · Apr 12, 2018

Where did you power up your Mavic and take off from?

Jameslavis · Apr 12, 2018

These are the best posts. Grab some popcorn and watch the forum detectives solve the case.

swooshdave · Apr 12, 2018

Jameslavis said:
These are the best posts. Grab some popcorn and watch the forum detectives solve the case.

As long as it was someone else's drone that got lost or damaged.

InvisibleName · Apr 12, 2018

Toyotamdt said:
I got some compass warning... I've flow here a bunch without issue. Crazy.

When did you get the warnings? Pre-take off or during flight? How may satellites were you locked on to? As suggested above, your flight log will soon be poured over by some of the detectives on here if you upload it.

kakao · Apr 12, 2018

I bet the OP is not coming back ..

Toyotamdt · Apr 12, 2018

Here it is... the flight record. Looks weird because it shows that I flew over the building, and I didn't. I went straight north, not over the building.

sar104 · Apr 12, 2018

Toyotamdt said:
Here it is... the flight record. Looks weird because it shows that I flew over the building, and I didn't. I went straight north, not over the building.

Which direction was it facing at takeoff? As in this view?

Toyotamdt · Apr 12, 2018

East... interesting, I didn't know there were pics in there. I'm new to this, is there a lot of pics or videos or what is that all about?

sar104 · Apr 12, 2018

Toyotamdt said:
East... interesting, I didn't know there were pics in there. I'm new to this, is there a lot of pics or videos or what is that all about?

That log contained one image, which I guessed was just after takeoff. So it was facing east - correct?

sar104 · Apr 12, 2018

The cause of the flight instability is pretty clear. You took off facing east, but the IMU yaw was initialized at -107°, i.e. WSW. That will have been due to magnetic interference at the takeoff location.

As a result of the significant error in heading, when the aircraft attempts to move or counter drift, it applies thrust in the wrong direction:

In this case the FC applies positive pitch, expecting to move backwards (east), but instead moves west - because it was facing east. That starts a chain event of incorrect corrections that manifest as uncontrolled flight.

If you retrieve the DAT file from the mobile device the magnetometer data should show the complete picture.

laurens23 · Apr 13, 2018

Toyotamdt said:
East... interesting, I didn't know there were pics in there. I'm new to this, is there a lot of pics or videos or what is that all about?

The log contains only up to the last 4 photos/video thumbnails, in low-resolution.

laurens23 · Apr 13, 2018

sar104 said:
The cause of the flight instability is pretty clear. You took off facing east, but the IMU yaw was initialized at -107°, i.e. WSW. That will have been due to magnetic interference at the takeoff location.

As a result of the significant error in heading, when the aircraft attempts to move or counter drift, it applies thrust in the wrong direction:

View attachment 35679

In this case the FC applies positive pitch, expecting to move backwards (east), but instead moves west - because it was facing east. That starts a chain event of incorrect corrections that manifest as uncontrolled flight.

If you retrieve the DAT file from the mobile device the magnetometer data should show the complete picture.

There have been several similar crashes. Would this be considered pilot error?

In the notifications it says:
Warning:In Flight, working compass encounters magnetic-field interference,please switch to atti mode if craft behave abnormally

Warning:In Flight, working IMU encounters heading exception,please switch to atti mode if craft behave abnormally

I don't think we can manually switch to ATTI mode even if we wanted to, right?

Why did the drone not switch to ATTI mode after these warnings? It seems like the drone correctly determined the issue, but asked the operator to take an action that was impossible (switch to ATTI).

lets hope the Mavic II will have a ATTI switch...

Simmo · Apr 13, 2018

#sar104 might be able to see more in the logs, but could it be that the error message is just badly written, and maybe a carry over from the Phantoms? Maybe its telling you that it has switched into, or going to switch into atti?? However, I do agree with you, having a switch so the operator knows one way or the other is better.

laurens23 · Apr 13, 2018

Simmo said:
#sar104 might be able to see more in the logs, but could it be that the error message is just badly written, and maybe a carry over from the Phantoms? Maybe its telling you that it has switched into, or going to switch into atti?? However, I do agree with you, having a switch so the operator knows one way or the other is better.

it did not switch to ATTI by itself, that would have been in the log. (It would also likely have avoided the crash)

I agree the notification might be a translation/copy paste issue, but it might also be enough to get a warranty repair from DJI, instead of a pilot error ruling and 30% discount for a new drone.

Simmo · Apr 13, 2018

Agreed.

Kevjones777 · Apr 13, 2018

Guys DJI need to address this somehow in the FW. Let's not forget that this drone is marketed as "easy to fly". Under normal conditions it is easy to fly, however as any pilot will tell you, you earn your money when things go wrong. This aircraft is actually a technological marvel and sophisticated enough to "know" that it is losing it's "marbles" so to speak and there should be some sort of auto failsafe mode that kicks in (not a RTH) maybe a stabilised hover or something, with a corresponding message on the controller to say "Auto Pilot" has taken over. This will give the pilot a chance to evaluate the situation and resume control when they are not in "panic" mode. It is so easy when this thing starts going "ma sugar" to lose your cool and forget about pause buttons etc.