Drone crash - what did I do?

[Benton BS]

I've flown my Mavic 2 a couple dozen times with no issue. Today, I took off and at about 20 ft - it just took off at full speed
circled out about 150 yards away...and get this - crashed into a headstone in a cemetery. Drone is toast. I hope I
attached the correct flight record. Hope someone can explain my misfortune. I'll assume operator error at this time

 

[Benton BS]

I've flown my Mavic 2 a couple dozen times with no issue. Today, I took off and at about 20 ft - it just took off at full speed
circled out about 150 yards away...and get this - crashed into a headstone in a cemetery. Drone is toast. I hope I
attached the correct flight record. Hope someone can explain my misfortune. I'll assume operator error at this time

I'm curious if this is operator error or something went wrong with the drone. As mentioned above, I don't believe I did
anything different on this flight. It literally got in the air and took off - the flight speeds show over 50 mph

 

[sar104]

It looks like another case of magnetic interference at the takeoff location.

Note that the yaw value is initialized at -116°. After takeoff, the yaw changes to -90° and forward elevator is applied, causing it to pitch forwards as expected. It should therefore move west, but it actually moves east.



That's reflected clearly in the GPS flight path, but note that the IMU initially thinks that it is moving west, based on its accelerometers and incorrect yaw value. It's probable that it was actually facing east. The mobile device DAT file contains the necessary magnetometer data to confirm that.

 

[MAvic_South_Oz]

After reading recent threads about the mag interference crashes here on the forum, I'm definitely noting to give this far more attention when setting up to fly.
Align drone north, and check on map, even if no warnings are given.

Am I right thinking this hasn't been a major issue with the MP, it seems to be more common now with the new range of Mavics ?

 

[Meta4]

Am I right thinking this hasn't been a major issue with the MP, it seems to be more common now with the new range of Mavics ?

It can happen in any DJI drone if launched from a location with suitable magnetic interference.

 

[Benton BS]

I left from a parking lot and no warning until it was well into flight. I had zero control
Until I picked up the pieces. Being a novice. I wish would have known what to look for prior to takeoff. Maybe it’s deep in all the instructions
Just don’t quite understand how or why there is absolutely no control once it left
During most of the flight it was over a field so there should have been minimal
Interference
Can I assume I have a total loss???

 

[Simmo]

Align drone north, and check on map, even if no warnings are given.

And you dont have to face North mate, that could be quite unsuitable at the launch site. Just make sure that the physical AC and the app are showing the same direction.

 

[MAvic_South_Oz]

It can happen in any DJI drone if launched from a location with suitable magnetic interference.

For sure, I've had the magnetic interference warnings if doing some downloading etc on a metal table (once when travelling), or if launching from the ground in some areas (2 or 3 times).
Very simple to just move a little or hand launch if taking off.

I'm talking about this major compass error where no warnings are given, but once corrected basically causes a fly away.

Is there a way to beat this if it happens ?
I read in another similar thread pause wont work . . . so what else would stop the fly away once the error happens, and before it loses controller signal ?

RTH would not work either I guess, so if fly away happens in this circumstance unless there is something you can do it's gone ?

 

[MAvic_South_Oz]

I left from a parking lot and no warning until it was well into flight. I had zero control
Until I picked up the pieces. Being a novice. I wish would have known what to look for prior to takeoff. Maybe it’s deep in all the instructions
Just don’t quite understand how or why there is absolutely no control once it left
During most of the flight it was over a field so there should have been minimal
Interference
Can I assume I have a total loss???

Benton, sorry mate, was completely perplexed by this issue myself, and how to stop it in flight (better of course to know what to do before taking off !), I completely overlooked your plight. :/
Sorry again, it must be so depressing to lose it so early into your new hobby.

There is another thread somewhere here about similar crash, and some say it is worth approaching DJI about some level of warranty.
Maybe others can give their experiences for you to gather and make a decision, nothing to lose I guess.

DJI don't advise anywhere to check for compass error (with no warnings) UAV pilots are just expected to pick up a warning if it appears and adjust their flight plans.

 

[Simmo]

I'm sure @Meta4 or @sar104 will have further info, but I'm thinking a 100% throttle down should bring the AC to the ground.
I'm pretty positive that in the logs I have looked at, throttle commands were being obeyed, its just that the other inputs are compromised or not doing what they are intended to do. Then a panic sets in and generaly throttle is not touched as the operator watches it crash.
I'm not saying that a throttle down will land the AC like its supposed to land!! But it could bring it down quicker and closer tyo you?

Only throwing it out there, happy to be proven wrong!!

 

[AnzacJack]

Scary that once it goes into this suicidal flyaway state, there is nothing that can be done.
Maybe setting up the atti mode from DJI ***? Would selecting atti mode stop it?
Haven’t had an issue like this since back in the blade qx days

 

[Meta4]

Just don’t quite understand how or why there is absolutely no control once it left
During most of the flight it was over a field so there should have been minimal interference

The problem was caused at the place you powered up the drone and it determined where north is.
What can you say about that location? What did you launch from?

I'm thinking a 100% throttle down should bring the AC to the ground.

It was flying so fast that it was all over quite quickly.
Also crashing it down at speed would probably have caused similar damage.

Scary that once it goes into this suicidal flyaway state, there is nothing that can be done.

Prevention is really the only way to deal with this kind of incident.
It usually so fast that it's over before the pilot even knows what's going on.

 

[Meta4]

Speed started to take off around 18 seconds and the crash was at 38 seconds with speeds up to 55 mph.

 

[Benton BS]

Speed started to take off around 18 seconds and the crash was at 38 seconds with speeds up to 55 mph.

Thanks all. Yes flight was over before I could even think about what to do next. The take off spot was a asphalt parking lot. We flew AC in small town only a few days previous so the interference issue never crossed my mind.

 

[Meta4]

The take off spot was a asphalt parking lot.

Asphalt is generally safe as it doesn't have steel reinforcing like concrete.
But it can sometimes cover steel plates or pipes etc that can cause this sort of issue.

 

[Bigbird48]

I was flying off my deck today and when I brought the bird home I decided to see if I could land on a small wood table about 20 Inches sq that was about 20 feet out in front of the deck well I landed ok but then got a compass error can not take off. Well the only metal are a couple of screws that hold the table top to the wood frame. Are these things so sensitive to metal that a wood screw can mess with the compass that seems like over kill to me.

 

[Meta4]

I was flying off my deck today and when I brought the bird home I decided to see if I could land on a small wood table about 20 Inches sq that was about 20 feet out in front of the deck well I landed ok but then got a compass error can not take off. Well the only metal are a couple of screws that hold the table top to the wood frame. Are these things so sensitive to metal that a wood screw can mess with the compass that seems like over kill to me.

There are two factors to consider.
The size of the steel object
The distance between the compass and the steel object.
A good sized steel screw at one inch has a bigger magnetic effect on the compass than 100000 tons of steel at this distance:

 

[Elude]

It looks like another case of magnetic interference at the takeoff meters....

What should a pilot do when they first notice this behavior (The drone wandering off due to mag interference)? Full down?

 

[Meta4]

What should a pilot do when they first notice this behavior (The drone wandering off due to mag interference)? Full down?

It's usually too late when you notice.
Awareness and prevention is much better.

 

[Kilrah]

Switch to ATTI, but unfortunately that's not something DJI considers people need to be able to do.