Please select Into the mobile phone version | Continue to access the computer ver.
Magnetic Field Interference. Exit P-GPS Mode.
123Next >
12193 98 2017-5-14
Uploading and Loding Picture ...(0/1)
o(^-^)o
fkindome
lvl.3
Flight distance : 130682 ft
Canada
Offline

I was out today on flying the Mavic Pro and after a few minutes at an altitude of 50m I get this warning..."Magnetic Field interferance. Exit  P-GPS Mode." Right after this message displayed for just a few seconds the Mavic took a life of its own...controls did not work and it started flying away at top speed. Satellite count was 17.  I knew there was a problem but what I do not understand is why does it not just hover at its current location but it decides to fly away. It gets veru scary when the controls do not work and it just keeps on flying away from the last location where the warning was given. Can someone explain to me what is going on and how to avoid such situations (there were no warnings during take-off). Warning was displayed when it got to about 50m up. How do I know certain about these magnetic fields?
By the way after it flew away for about 2 mins I saw that I had controls back then I activated RTH which brought it back.
Any clues?






2017-5-14
Use props
dronist
Captain
United States
Offline

What happened is it went into ATTI mode which means YOU have to take control and bring it home. it feels like it flying on its own but it is like hanging in the air and the wind is pushing it around.

I suggest buying a cheap drone to practice ATTI mode on it and also practice in the academy.
2017-5-14
Use props
fkindome
lvl.3
Flight distance : 130682 ft
Canada
Offline

dronist Posted at 2017-5-14 20:15
What happened is it went into ATTI mode which means YOU have to take control and bring it home. it feels like it flying on its own but it is like hanging in the air and the wind is pushing it around.

I suggest buying a cheap drone to practice ATTI mode on it and also practice in the academy.

How can one fly in ATTI mode if both controls do not work? Yes, the drone was set to ATTI mode but I could not control it.
Some information on this is given in this thread:   https://forum.dji.com/thread-95943-1-1.html
2017-5-14
Use props
DJI Mindy
Administrator
Flight distance : 7 ft
Online

Could you please sync your flight records then provide me with your DJI account email and the date this occurred? I'll help to review it.
2017-5-15
Use props
DroneFlying
Captain
Flight distance : 10774613 ft
United States
Offline

fkindome Posted at 2017-5-14 20:58
How can one fly in ATTI mode if both controls do not work? Yes, the drone was set to ATTI mode but I could not control it.
Some information on this is given in this thread:   https://forum.dji.com/thread-95943-1-1.html

It probably said ATTI mode but it's much more likely that it was in what I call BATTI mode, in which case practicing in ATTI mode on some other drone model won't help. I believe that any time the Mavic finds itself without GPS and VPS that it reports that as ATTI, even if the compass data is also missing or invalid. This is a problem that used to be pretty common and even people with experience piloting (for example) Phantoms in (true) ATTI mode say that what they experienced with the Mavic is something very different.

Can you please upload the flight log from your mobile device and also the DAT file from the Mavic itself?
2017-5-15
Use props
hallmark007
Captain
Flight distance : 4199094 ft
  • >>>
Ireland
Offline

When you enter area with magnetic interference your aircraft compass will go a little crazy what ever the heading of the compass gps will follow that, to know if your aircraft was responding to stick movements. You should upload your logs to phantomhelp or airdata, this is not a fault with the aircraft but rather a fault with the environment you were flying in.
Also just because your telemetry says you have 17 satellites doesn't mean anything unless your bar graph is showing good signal.

http://www.phantomhelp.com/LogViewer/Upload/
2017-5-15
Use props
hallmark007
Captain
Flight distance : 4199094 ft
  • >>>
Ireland
Offline

fkindome Posted at 2017-5-14 20:58
How can one fly in ATTI mode if both controls do not work? Yes, the drone was set to ATTI mode but I could not control it.
Some information on this is given in this thread:   https://forum.dji.com/thread-95943-1-1.html

The link you provided does not have anything to do with magnetic interference. You will find out more if you put up your flight log.
2017-5-15
Use props
fkindome
lvl.3
Flight distance : 130682 ft
Canada
Offline

OK...So I uploaded flight log to PhantomHelp....and I'm seeing a lot of stuff...wow.....Yaw error.....Speed Error....
http://www.phantomhelp.com/LogViewer/GEHZD7PKBQBOCX9BXMY3/
2017-5-15
Use props
DroneFlying
Captain
Flight distance : 10774613 ft
United States
Offline

fkindome Posted at 2017-5-15 05:36
OK...So I uploaded flight log to PhantomHelp....and I'm seeing a lot of stuff...wow.....Yaw error.....Speed Error....
http://www.phantomhelp.com/LogViewer/GEHZD7PKBQBOCX9BXMY3/

Did you take off from the sidewalk and when and where did you last calibrate your compass? More specifically, how confident are you that you were well away from any metal / magnetic interference when you performed your last calibration?
2017-5-15
Use props
fkindome
lvl.3
Flight distance : 130682 ft
Canada
Offline

DroneFlying Posted at 2017-5-15 05:52
Did you take off from the sidewalk and when and where did you last calibrate your compass? More specifically, how confident are you that you were well away from any metal / magnetic interference when you performed your last calibration?

This was in a small park and I needed to capture the front of an entrance. I took off from the side walk. Last compass calibration was a week ago in an open field...another park with lots of greens and I do not think that was close to metals.
2017-5-15
Use props
DroneFlying
Captain
Flight distance : 10774613 ft
United States
Offline

fkindome Posted at 2017-5-15 06:02
This was in a small park and I needed to capture the front of an entrance. I took off from the side walk. Last compass calibration was a week ago in an open field...another park with lots of greens and I do not think that was close to metals.

I took off from the side walk.

That's what I suspected, and that's probably what caused this to occur. Concrete usually contains (steel) rebar that will create compass problems that in turn lead to behavior like this during flight.

I'm guessing that before takeoff the application displayed a message that reads something like, "Magnetic interference; move aircraft or calibrate compass", which essentially means that you shouldn't take off from that location. Unfortunately that message never gets included in the log because it's not generated during flight.

You should consider buying a landing pad to use when you need a place to take off in urban and suburban areas where only grass and concrete are available.

2017-5-15
Use props
BudWalker
First Officer
Flight distance : 150919 ft
  • >>>
United States
Offline

DroneFlying Posted at 2017-5-15 06:08
I took off from the side walk.

That's what I suspected, and that's probably what caused this to occur. Concrete usually contains (steel) rebar that will create compass problems that in turn lead to behavior like this during flight.

Another way to see a problem exists is to look at the red triangle in the Go App and verify that it's pointing in the right direction. Often there is no "Mag Interference..." message, but the red triangle will show there is a problem.
2017-5-15
Use props
hallmark007
Captain
Flight distance : 4199094 ft
  • >>>
Ireland
Offline

fkindome Posted at 2017-5-15 05:36
OK...So I uploaded flight log to PhantomHelp....and I'm seeing a lot of stuff...wow.....Yaw error.....Speed Error....
http://www.phantomhelp.com/LogViewer/GEHZD7PKBQBOCX9BXMY3/

When you got mag interference your log shows AC went into Atti mode , it also shows you pushing on the throttle and the aircraft responding by increasing height from approx 168 ft to 400ft your log shows no other stick movements only throttle, as you were getting higher your aircraft was drifting faster on the wind until you regained proper gps and compass. This lasted approximately 1 minute in this period it only shows you throttling up and aircraft was reacting.
I think this mishap was down to your environment and not the aircraft, I don't think it was a problem with your compass , but I would try a different area start your aircraft and check your compass reading in the app.
But one thing is certain your aircraft was responding in Atti mode to your input because it's not possible for your aircraft to blow up 240 feet ,
2017-5-15
Use props
fkindome
lvl.3
Flight distance : 130682 ft
Canada
Offline

hallmark007 Posted at 2017-5-15 08:15
When you got mag interference your log shows AC went into Atti mode , it also shows you pushing on the throttle and the aircraft responding by increasing height from approx 168 ft to 400ft your log shows no other stick movements only throttle, as you were getting higher your aircraft was drifting faster on the wind until you regained proper gps and compass. This lasted approximately 1 minute in this period it only shows you throttling up and aircraft was reacting.
I think this mishap was down to your environment and not the aircraft, I don't think it was a problem with your compass , but I would try a different area start your aircraft and check your compass reading in the app.
But one thing is certain your aircraft was responding in Atti mode to your input because it's not possible for your aircraft to blow up 240 feet ,

The thing is the just before getting into ATTI mode the log shows a Yaw Error....and there are several Speed Errors too....so far no one has said anything about these.

The thing with the AC starting speeding away out of control and the first thought was to raise elevation to avoid obstacles because I was fairly close to trees and buildings. It was not that windy for it to be blown that fast away....unless I'm being made to understand that throttle up means fast-forward....a bit confused.
2017-5-15
Use props
fkindome
lvl.3
Flight distance : 130682 ft
Canada
Offline

DroneFlying Posted at 2017-5-15 06:08
I took off from the side walk.

That's what I suspected, and that's probably what caused this to occur. Concrete usually contains (steel) rebar that will create compass problems that in turn lead to behavior like this during flight.

Great recommendations...I actually have a landing pad but did not use it.
2017-5-15
Use props
DroneFlying
Captain
Flight distance : 10774613 ft
United States
Offline

fkindome Posted at 2017-5-15 09:29
Great recommendations...I actually have a landing pad but did not use it.

Technically you can probably take off from the sidewalk if you avoid being too close to the rebar, which is laid out in a grid and has gaps; I've done it myself many times without any problems. The trick is just to make sure that you aren't seeing the "Magnetic interference" message I mentioned (or the icon pointing in the wrong direction as BudWalker said) before you take off. If you do see that message just move the aircraft a short distance away until the message is no longer displayed.

But yes, the safest and simplest approach is just to avoid the sidewalk altogether and use a landing pad over a spot where you know there's no metal. That's my preferred approach and is what I do most of the time; others advocate hand launching, but it's not something I personally recommend.
2017-5-15
Use props
hallmark007
Captain
Flight distance : 4199094 ft
  • >>>
Ireland
Offline

fkindome Posted at 2017-5-15 09:28
The thing is the just before getting into ATTI mode the log shows a Yaw Error....and there are several Speed Errors too....so far no one has said anything about these.

The thing with the AC starting speeding away out of control and the first thought was to raise elevation to avoid obstacles because I was fairly close to trees and buildings. It was not that windy for it to be blown that fast away....unless I'm being made to understand that throttle up means fast-forward....a bit confused.

Regarding timing, they were all very close speed yaw and Speed and so on, although not 100% sure, speed and yaw movements were caused because of interference from compass and aircraft going into Atti mode.

Your movement to raise AC was the correct one and that saved your Mavic from crashing, raising your aircraft always gives you more time to get your bearings. but the simple fact that you were able to raise your AC shows that it was responsive almost instantly and Atti mode works as it should.

My advice to you is to go to a safe area start your AC and if compass is ok DO NOT calibrate as doing a calibration can sometimes lead to more problems than you need.
Good Luck
2017-5-15
Use props
fans18d204c5
lvl.3
Flight distance : 1162605 ft
United States
Offline

i had the exact same thing happen to me on Saturday. I got hte warning and it felt like the drone just was erraticaly hovering. Fortunately i didn't have more than a few hundred feet from me and after about 2 minutes, GPS was restored on his own and things went back to normal.  
2017-5-15
Use props
fans18d204c5
lvl.3
Flight distance : 1162605 ft
United States
Offline

DJI Mindy Posted at 2017-5-15 01:05
Could you please sync your flight records then provide me with your DJI account email and the date this occurred? I'll help to review it.

I had the exact same thing happen to me. I'll forward my flight info to you as well later today.
2017-5-15
Use props
fans18d204c5
lvl.3
Flight distance : 1162605 ft
United States
Offline

DroneFlying Posted at 2017-5-15 06:08
I took off from the side walk.

That's what I suspected, and that's probably what caused this to occur. Concrete usually contains (steel) rebar that will create compass problems that in turn lead to behavior like this during flight.

Mine did the same thing and I was in a park flying over turf. I've flown in the same area several times with no issues.
2017-5-15
Use props
DroneFlying
Captain
Flight distance : 10774613 ft
United States
Offline

fans18d204c5 Posted at 2017-5-15 10:02
Mine did the same thing and I was in a park flying over turf. I've flown in the same area several times with no issues.

If you'd like to upload the flight log from your mobile device using the directions on PhantomHelp and provide a link to it in this thread we'll take a look.
2017-5-15
Use props
fkindome
lvl.3
Flight distance : 130682 ft
Canada
Offline

BudWalker Posted at 2017-5-15 06:11
Another way to see a problem exists is to look at the red triangle in the Go App and verify that it's pointing in the right direction. Often there is no "Mag Interference..." message, but the red triangle will show there is a problem.

Please can you post a pic of this  "red triangle in the Go App" if you can...just to be sure I have it right...thanks.
2017-5-15
Use props
DroneFlying
Captain
Flight distance : 10774613 ft
United States
Offline

fkindome Posted at 2017-5-15 14:35
Please can you post a pic of this  "red triangle in the Go App" if you can...just to be sure I have it right...thanks.

He's talking about the aircraft symbol in the map view of the Go app; it's rendered as a red triangle that's normally pointing in the same direction as the aircraft, but when the compass information is off it points in the wrong direction.
2017-5-15
Use props
fans18d204c5
lvl.3
Flight distance : 1162605 ft
United States
Offline

DJI Mindy Posted at 2017-5-15 01:05
Could you please sync your flight records then provide me with your DJI account email and the date this occurred? I'll help to review it.

Kds1041@yahoo.com   date 5/13/2017
2017-5-15
Use props
fans18d204c5
lvl.3
Flight distance : 1162605 ft
United States
Offline

DJI Mindy Posted at 2017-5-15 01:05
Could you please sync your flight records then provide me with your DJI account email and the date this occurred? I'll help to review it.

Kds1041@yahoo.com   date 5/13/2017
2017-5-15
Use props
fans18d204c5
lvl.3
Flight distance : 1162605 ft
United States
Offline

DroneFlying Posted at 2017-5-15 10:04
If you'd like to upload the flight log from your mobile device using the directions on PhantomHelp and provide a link to it in this thread we'll take a look.

http://www.phantomhelp.com/LogViewer/M7BVJ0JHHI4LHP373FSZ/
2017-5-15
Use props
DroneFlying
Captain
Flight distance : 10774613 ft
United States
Offline


It looks like your case is similar to the one earlier, except that instead of taking off from a sidewalk you took off from a parking lot. To avoid problems like this make sure there's no steel underneath the aircraft or anything else nearby that can affect the compass. For example, that grassy area in front of the parking spaces would have been a better choice of takeoff location.
2017-5-15
Use props
hallmark007
Captain
Flight distance : 4199094 ft
  • >>>
Ireland
Offline

fans18d204c5 Posted at 2017-5-15 16:09
http://www.phantomhelp.com/LogViewer/M7BVJ0JHHI4LHP373FSZ/

Hi 204c5, your log is almost identical to the OP's, you also hit serious magnetic interference and went into Atti your aircraft was also responding to your stick movements, the odd yaw movements could be to do with the wind.
For a fair bit of your flight you were loosing radio signal. But I suppose lucky RTH worked.
Was there anything in your area that might have interfered with compass like steel roof or interference on the ground prior to taking off.
2017-5-15
Use props
fans18d204c5
lvl.3
Flight distance : 1162605 ft
United States
Offline

hallmark007 Posted at 2017-5-15 16:46
Hi 204c5, your log is almost identical to the OP's, you also hit serious magnetic interference and went into Atti your aircraft was also responding to your stick movements, the odd yaw movements could be to do with the wind.
For a fair bit of your flight you were loosing radio signal. But I suppose lucky RTH worked.
Was there anything in your area that might have interfered with compass like steel roof or interference on the ground prior to taking off.

Nothing. I was in a soccer field.No metal or anything. I hit the RTH button and nothing happened  until I got gps mode back. It was bizzare.
2017-5-15
Use props
fans18d204c5
lvl.3
Flight distance : 1162605 ft
United States
Offline

DroneFlying Posted at 2017-5-15 16:27
It looks like your case is similar to the one earlier, except that instead of taking off from a sidewalk you took off from a parking lot. To avoid problems like this make sure there's no steel underneath the aircraft or anything else nearby that can affect the compass. For example, that grassy area in front of the parking spaces would have been a better choice of takeoff location.

I was over the soccer field when the interference warning  popped on.No metal anywhere.
2017-5-15
Use props
SkunkWerxs
Second Officer
Flight distance : 231217 ft
United States
Offline

hallmark007 Posted at 2017-5-15 16:46
Hi 204c5, your log is almost identical to the OP's, you also hit serious magnetic interference and went into Atti your aircraft was also responding to your stick movements, the odd yaw movements could be to do with the wind.
For a fair bit of your flight you were loosing radio signal. But I suppose lucky RTH worked.
Was there anything in your area that might have interfered with compass like steel roof or interference on the ground prior to taking off.

Hey Hall , What you said earlier in the thread about the Flying Environment area maybe the possible
               cause for the issue and now almost the same issue with another op , I looked and zoomed
               out at there satellite maps and found the two to be close to an Industrial and Land Development
               areas and one was close to a airport also , Your Theory about there flying Environment
               is strongly looking like this is the cause in my opinion .
FlySafe-FlyFree   
                  
2017-5-15
Use props
DroneFlying
Captain
Flight distance : 10774613 ft
United States
Offline

fans18d204c5 Posted at 2017-5-15 17:23
I was over the soccer field when the interference warning  popped on.No metal anywhere.

I understand, but I suspect that the compass problem was induced by the steel in the parking lot from which you took off, which is essentially what happened in the case discussed earlier in this thread. If you want us to be really sure then you can upload the DAT file from the flight using the instructions here and then provide a link to the file in DropBox.
2017-5-15
Use props
fkindome
lvl.3
Flight distance : 130682 ft
Canada
Offline

DroneFlying Posted at 2017-5-15 18:02
I understand, but I suspect that the compass problem was induced by the steel in the parking lot from which you took off, which is essentially what happened in the case discussed earlier in this thread. If you want us to be really sure then you can upload the DAT file from the flight using the instructions here and then provide a link to the file in DropBox.

I still do not seem to understand this. What you are saying is that an issue is detected before take-off...yet the AC flies normally for quite a fair bit. For the 2nd poster, he actually flew for quite a while before the issue came up. Why does the AC take off if there is a compass problem.
2017-5-15
Use props
fkindome
lvl.3
Flight distance : 130682 ft
Canada
Offline

DJI Mindy Posted at 2017-5-15 01:05
Could you please sync your flight records then provide me with your DJI account email and the date this occurred? I'll help to review it.

findome@yahoo.com
Date: May 14, 2017
2017-5-15
Use props
DroneFlying
Captain
Flight distance : 10774613 ft
United States
Offline

fkindome Posted at 2017-5-15 21:10
I still do not seem to understand this. What you are saying is that an issue is detected before take-off...yet the AC flies normally for quite a fair bit. For the 2nd poster, he actually flew for quite a while before the issue came up. Why does the AC take off if there is a compass problem.

Why does the AC take off if there is a compass problem.

I suppose it's debatable whether you should be able to take off when there's magnetic interference, but it's most definitely possible and easy to see this for yourself, such as if you take off from the roof of a car as some people have done.
2017-5-16
Use props
hallmark007
Captain
Flight distance : 4199094 ft
  • >>>
Ireland
Offline

fkindome Posted at 2017-5-15 21:10
I still do not seem to understand this. What you are saying is that an issue is detected before take-off...yet the AC flies normally for quite a fair bit. For the 2nd poster, he actually flew for quite a while before the issue came up. Why does the AC take off if there is a compass problem.

Here's a video that might give you a better understanding

2017-5-16
Use props
hallmark007
Captain
Flight distance : 4199094 ft
  • >>>
Ireland
Offline

fans18d204c5 Posted at 2017-5-15 17:23
I was over the soccer field when the interference warning  popped on.No metal anywhere.

Check out post 36 video might help you understand.
2017-5-16
Use props
BudWalker
First Officer
Flight distance : 150919 ft
  • >>>
United States
Offline

IMHO  fan18d204cd's incident was not a launch-from-a-geomagneticaly-distorted-site incident. If it had been then erratic flight would have occured immediately after launch. Also, these incidents occur because the switch to ATTI is not done as it should be. Typically, a compass error isn't declared.

The thing to note about this incident is that there was a SPEED_ERROR_LARGE at 524 followed by a YAW_ERROR_LARGE and then gpsHealth drop from 0 to 5 at 529. Finally, the switch to ATTI at 530. This could have been caused by a turbulence. The Flight Controller gives up and asks the pilot to do the navigating.

The only way to know for sure is to retrieve and provide the .DAT.
XX.jpg
2017-5-16
Use props
fkindome
lvl.3
Flight distance : 130682 ft
Canada
Offline

I'm beginning to think this erratic behavior of the Mavic when it complains about  "Magnetic Field Interference. Exit P-GPS Mode" is a BUG!
The message leads to a flyaway of the AC and I think DJI (if someone is reading) should seriously look into it and provide a patch. One possible fix is for the AC to activate and auto RTH similar to cases where it loses signal.

I just cannot understand why it should fly away on a compass error instead of going home. In my case it was a waste of energy and a waste of resources. I was just about 50m up (altitude) and it would have taken the AC a few seconds to just "drop" back home instead of flying away. I have read on a few forums including the P3 that this is a problem and it is also happening with the Mavic Pro but not on the Inspire. It is my hope that DJI would look into this issue.
2017-5-16
Use props
hallmark007
Captain
Flight distance : 4199094 ft
  • >>>
Ireland
Offline

fkindome Posted at 2017-5-16 14:32
I'm beginning to think this erratic behavior of the Mavic when it complains about  "Magnetic Field Interference. Exit P-GPS Mode" is a BUG!
The message leads to a flyaway of the AC and I think DJI (if someone is reading) should seriously look into it and provide a patch. One possible fix is for the AC to activate and auto RTH similar to cases where it loses signal.


As I explained to you earlier your Aircraft didn't fly away it went into Atti mode and if you read your logs it responded to your stick movements, you chose to raise your aircraft which was the right move, but while you were doing this your aircraft was drifting in Atti mode if you had used other stick movements you could have controlled your aircraft but Atti mode is not easy, and you were lucky you regained gps and stability.
My conclusion is the environment you were flying in was effecting your aircraft where the interference was coming from I do not know, but it was there.

Even if rth had kicked in your Aircraft would follow compass heading so for this was lucky because it could have flown around in circles trying to get its bearing .

If you lost signal with remote it would have returned home as long as you had gps.
2017-5-16
Use props
123Next >
Advanced
You need to log in before you can reply Login | Register now

Credit Rules