Hi,
I have a fairly new mavic pro, bought it on 1. of March 2018.
I would say I have some experience flying. I have a self built racing drone. Got the mavic to get some nice footage from here and there.

I took it with me on my latest vacation and wanted to film in Tenerife. I already flew it near the National Park (not in the park itself) without problems.

Today, on the 21st of May 2018, when attempting to film one of the marinas, the drone's compass seemed to misbehave and I lost control. The drone started to drift one sided and to lose height quiet rapidly. I successfuly managed to manouver it away from the water on to an empty partking lot, where it crashed. There was damage to the drone: the lens, the gimbal and the plastic body got a few scratches. Besides that, the motors start again. I did not attempt to fly it again, though.

I could retrieve the footage [0] and the log entry [1] from this flight.

To me it seems like a technical issue which should be covered by DJI.

I wanted to get some inside from the community, whether you have experienced such a behaviour before and how to present it to DJI?

Thanks for reading and for your replies in advance.

[0]
[1] http://www.phantomhelp.com/LogViewer/EW5NBPD997YD9EX0V4MS/

Why did you continue with the flight after constant warnings? Did you confirm aircraft position compared with the map before take off? Sorry for your loss but I'm going to call pilot error. You should have changed location to remove the flawed compass readings. Good luck.

Hi aiQon, I am sorry to hear on what happened to your drone. Good thing that you were able to manage it back to the land. I recommend that you send in the unit to our facility for a repair to diagnose the problem and fix the issue. No worry, we have our Analyst team who will review the flight record. If found out that it is product malfunction and in warranty, then the repair will be covered by DJI. To start the request for a repair, you may click on this link https://repair.dji.com/repair/index . Thank you.

Took a look at your flight log, pretty much had serious compass errors from the start, you maintained P-GPS for a few seconds then went into Atti Mode, I agree should not have taken off. Watch below

Everything was green during take off, the error kicked in like 4s after start. I realized something is wrong and immediately tried to remedy permanent damage. 13s later it crashed.

Where do you see that the compass error was present right from the start?

GPS coordinates were accurate during start as can be seen in the log. I had no indication that something is flawed. First indication came in 4s after take off. Drone was above water by then and I immediately lost control.

I mean the log says yaw error. So there Must be something fishy besides the compass misbehaving.

The drone did not report miscalculation neither. There was no sign not to start.

In case your specialists deduce there is no error. Can I get the drone checked by an independent third party?

You had compass warnings right from the get go, as soon as you took off, you almost immediately pushed elevator 100% and throttle 90% , causing aircraft to go forward and up because you had compass problems and now in Atti mode aircraft was difficult to control.

Looking at your take off point which was a concrete wall or pavement, it’s most likely you picked up magnetic interference there which caused your problems.

aiQon Posted at 2018-5-21 14:45
Everything was green during take off, the error kicked in like 4s after start. I realized something is wrong and immediately tried to remedy permanent damage. 13s later it crashed.

Where do you see that the compass error was present right from the start?

The compass error wasn’t there from the start but as soon as you took off at height of 3 feet it was you should have just pushed left stick down to land, but you pushed right stick up and left stick up.

I have to agree, that this happened due to pilot error. Never take off from concrete... you can't know if it's enforced. Never take off if you are near any kind of metal.
I'm sorry for what happened, but I'm convinced that this won't be covered by DJI.

You can clearly see just 3.9 seconds and just 2.6 feet up you were getting compass errors and went to atti mode.  At that point you should of just landed it immediately and you would of been good.  Agree with others this will not be covered as you continued to take it out after 3 feet.  Sorry for your loss.

aiQon Posted at 2018-5-21 14:45
Everything was green during take off, the error kicked in like 4s after start. I realized something is wrong and immediately tried to remedy permanent damage. 13s later it crashed.

Where do you see that the compass error was present right from the start?

AC was in Atti mode at 2.9 seconds after takeoff, you started getting compass error at 3.9 seconds after take off, to me that is right from the start. if the App didn't warn you immediately (which it has been known to do) then you wouldn't have known, but the AC data is definitive. The RC display would/should have shown Atti mode 3 seconds after you took off.

I didn't read through it all but this is obvious that the METAL RAILS messed the compass. No brainer. Pilot error.

It’s not really about pilot error or not it’s more about understanding what happened and how it happened. None of us are a million miles from this.

We have a number of posts like this, with Compass errors very quickly after take off.  I don't believe the bird knows that it has the compass issue if you turn it on near something metal until you move it.  The compass goes where it goes on startup, and not until the aircraft is moved does it recognize the compass has not changed in proportion with the IMU.

In this case, the metal in the concrete and the rails likely messed with the compass and as soon as it moved a tiny bit, the compass and IMU were out of sync.

If I'm in an unknown environment I try to turn on the drone in one spot and walk a handful of feet to the launch location.  I might get compass calibration notices by doing this.  That's not a failsafe, but it helps in some cases and is easy to do.

Looks like you took off from pier made of concrete?  
Almost guaranteed there is large rebar in concrete, possibly even steel beams, and steel pylons that would cause magnetic interference.  
Also appears that very near where you took off from, there is metal guard rail that could have caused magnetic interference.  

From video it looks like you flew very close to metal guard rail (TM: 8s) during takeoff.   Drone may have been crossing over metal railing when it finally went out of control (TM: 14s).  
In video it looks like drone starts over railing then drifts back and to left, then turns to right.

FlyDK Posted at 2018-5-21 15:21
I have to agree, that this happened due to pilot error. Never take off from concrete... you can't know if it's enforced. Never take off if you are near any kind of metal.
I'm sorry for what happened, but I'm convinced that this won't be covered by DJI.

Never take off from concrete... you can't know if it's enforced

Right assumption with concrete is it does have steel reinforcing.  Reason is, concrete is incredibly strong under compression.  Whereas, concrete is weak under tension.  Thus need to use metal reinforcing in concrete structures.  Question is - How much reinforcing was used, and how much magnetic interference is caused by reinforcing?

From testing I have done, you can detect magnetic interefence to Earth's magnetic field caused by unknown or hidden sources such as steel reinforcing in concrete.

I have been to the marina today. Recalibrated everything. Went to the same spot. Carried the drone around, all was good. Then I put it on the exact same spot and lift it by hand, this time slower. Everything went red and it reported a compass error.

What I learn from this is to not take off from concrete and to carry the AC around a little to make sure there is no magnetic field to interrupt its start. Oh and don’t go 100% from launch point.

Thanks for the valuable information and your time.

Maybe DJI can collect magnetic interference information from its ACs and use it to display this as an additional warning. Like 8 of 10 pilots had compass errors here.
This would need to be packed in law and data privacy conform packing. Just an idea.

aiQon Posted at 2018-5-21 23:49
Maybe DJI can collect magnetic interference information from its ACs and use it to display this as an additional warning. Like 8 of 10 pilots had compass errors here.
This would need to be packed in law and data privacy conform packing. Just an idea.

Here check this video out it will help understand.

aiQon Posted at 2018-5-21 23:49
Maybe DJI can collect magnetic interference information from its ACs and use it to display this as an additional warning. Like 8 of 10 pilots had compass errors here.
This would need to be packed in law and data privacy conform packing. Just an idea.

This is what I would recommend safe distance from magnetic interference.

Natural and Artificial Magnetic Anomalies Warning

The following information has not been objectively tested to determine it’s impact on a Drones compass accuracy in flight.
        1        Many things can distort the earth’s magnetic field in the area you are flying:
        •        Steel framed or reinforced concrete buildings, bridges and roadways, iron pipes and culverts, high power electric lines, heavy equipment, trucks and automobiles, steel tanks, electric motors and even computers.
        •        Flying between steel framed or reinforced high rise buildings will distort the magnetic field in addition to causing GPS problems.

        2        Safe distances for compass calibration
        •        6” (15 cm) minimum: Metal rim glasses, pen/pencil, metal watch band, pocket knife, metal zipper/buttons, belt buckle, batteries, binoculars, cell phone, keys, camera, camcorder, survey nails, metal tape measure.
        •        18” (50 cm) minimum: Clipboard, data collector, computer, GPS antenna, 2-way radio, , cell phone case with magnetic closure.
        •        6 ft (2 m) minimum: Bicycle, fire hydrant, road signs, sewer cap or drain, steel pole,  guy wire, magnets, chain-link fence, bar-wire fence, data collectors
that use a magnet to hold the stylus.
        •        15 ft (5 m) minimum: Electrical box, small car/truck, powerline, building with concrete & steel.
        •        30 ft (10 m) minimum: Large truck, metal building, heavy machinery.

Something I believe we all should do is when the HP is set, and that sexy lady says 'check it on the map'... not only should you be checking the location, but the direction of the arrow, compared to the physical direction of the AC. They need to be the same. Its a quick check, should be done everytime.

I would be looking at where you took off from.The large slab of concrete would have probably
been full of steel reo this would cause your compass to go hey wire

DJI Natalia Posted at 2018-5-21 14:05
Hi aiQon, I am sorry to hear on what happened to your drone. Good thing that you were able to manage it back to the land. I recommend that you send in the unit to our facility for a repair to diagnose the problem and fix the issue. No worry, we have our Analyst team who will review the flight record. If found out that it is product malfunction and in warranty, then the repair will be covered by DJI. To start the request for a repair, you may click on this link https://repair.dji.com/repair/index . Thank you.

Is it not possible for DJI product owners to send the logs, flight data and then DJI team will find out if it is product issue and comes under warranty? Is there a need to send a product always before DJI concludes? Because flight data is the most important thing to check for error?

aiQon Posted at 2018-5-21 23:46
I have been to the marina today. Recalibrated everything. Went to the same spot. Carried the drone around, all was good. Then I put it on the exact same spot and lift it by hand, this time slower. Everything went red and it reported a compass error.

What I learn from this is to not take off from concrete and to carry the AC around a little to make sure there is no magnetic field to interrupt its start. Oh and don’t go 100% from launch point.

Try loading an App on your Android or iPhone that detects Magnetic Interference to Earth's Magnetic Field.  Then walk around a few areas watching App's output.  Lastly go back to Marina and check out general area, then specific takeoff spot and metal railing.

From all testing I have done, with three Gauss or Tesla Magnetic Field Apps; they will show unknown and hidden sources of Magnetic Interference.
As you walk around, you will see normal Earth's Magnetic Field for area.  As you get close (48-inches or less) to sources of Magnetic Interference you will start to see a deviation from normal Magnetic Field.  

In case of steel rebar in concrete, you may have to get Android or iPhone within 4-inches of concrete (simulate you drone at takeoff), because rebar is not at surface of concrete.
In case of steel railing, it may start showing deviations when you get Android or iPhone within 18-inches of railing.

An exmaple:  

Two peaks are when iPhone was moved over steel guard rail.  The sharp dip was when iPhone got close to large steel building.
The smooth area (46 to 48 microTesla) is normal field strength for aera.



Approximate, normal Magnetic Field for Santa Cruz de Tenerife (N29.2539, W16.6299) is 38.5 microTesla

Parik Posted at 2018-5-22 03:25
Is it not possible for DJI product owners to send the logs, flight data and then DJI team will find out if it is product issue and comes under warranty? Is there a need to send a product always before DJI concludes? Because flight data is the most important thing to check for error?

Hello, aiQon. Thank you for your response. It will be best though to send in the unit so that our repair team will be able to check the physical damages of the aircraft. At the same time, if you will sync and send us the flight record it will determined if the issue is caused by the product malfunction or pilot error.