Hi All, I am all new to drone flying, and here, I have a question want to seek for everyone’s help....

I ordered some model decals trying to decorate my Mavic Air a little, and found out some of them are actually metal decals when I received it, it’s kind of small, 15mm x 3mm but then, when I use a white board magnet to try, it could pick it up....

Now since the drone has a pretty sophisticated compass system, I wonder if these little decals would affect the compass performance?

Thanks a lot for your help, and I apologise if this question sounds too silly.....  

if the magnetic field is constant then you 'should' be ok, personally I wouldn't bother as who wants a fiat branded drone?

I think you will be ok.

Not sure about that, looks cool btw

And welcome to the forum buddy, hopefully someone can give you the right answer

Should be fine though I personally would not chance it

Thanks all..... well, i’ve put them on anyway, Will just give it a safe flight check and observe before going wild

I quite like the result at the end

The documentation reveals not payloading nor applying external unless blessed off

fans3eaf9bee Posted at 4-8 08:24
Thanks all..... well, i’ve put them on anyway, Will just give it a safe flight check and observe before going wild

I quite like the result at the end

Wish I had seen post sooner...

Would have suggested checking drone's compass interference levels in three different locations before and then afterwards.  A decrease or increase in levels would indicate potential problem.

The decals won’t effect your compass, but you must first calibrate your compass with them on, and if you need to take them off.
We see this method being used by users adding trackers all the time with no problems.


Calibration gives the compass the information it needs to determine which magnetic influences are part of the Mavic and what is the earth's normal magnetic field.
The compass doesn't lose calibration and doesn't ever need re-calibration unless you add or remove equipment to/from the Mavic, in this case adding .

And although we see with new drones more and more asking for calibration, this is down to a change seen on new drones by dji and a failsafe of not allowing you to fly until you carry out a correct calibration .

Well even estimating 3% negative effect (wich is a really bad approx.) I would never stick this this to my AC -- I well understand its your style but remember, safety first.
As an advice, you can stick a note with your phone number as in the event of a crash you can recover at least some parts and the SD card.

fans3eaf9bee Posted at 4-8 08:24
Thanks all..... well, i’ve put them on anyway, Will just give it a safe flight check and observe before going wild

I quite like the result at the end

I like the one to the rear - understated and elegant

After little more thought, one concern came to mind.  You mentioned "when I use a white board magnet to try, it could pick it up".  There is possibilty those particular metal decals became magnatized.  Similar to magnetizing tips of screw drivers.


How much of an impact on drone's compass accuracy could be caused by calibrating compass to compensate for sources of magnetic interference attached to drone, is unknown.  Think of it this way.  Normally compass calibration is to correct for local deviations from earth's magnetic field.  With addition of ferrous metal, compass calibrations are attempting to compensate for local deviations tied to earth, and from deviations that are tied to drone.  


We do know some ferrous metals in drone's have become magnetized.  Resulting in problems with drone's compass.  Requiring drone be degaussed.  Couple of companies sell drone degaussing tools.


Please do let us know how your drone flies.  Along with whether you have any problems in future with repeated compass calibration nags.


Happy Flying!

I see the troll has started up again, maybe show a bit of respect for the OP, and don’t try confuse his issue with BS .

elberti Posted at 4-9 03:17
Well even estimating 3% negative effect (wich is a really bad approx.) I would never stick this this to my AC -- I well understand its your style but remember, safety first.
As an advice, you can stick a note with your phone number as in the event of a crash you can recover at least some parts and the SD card.

thanks for your opinion, I see your point... to the precision of the drone, 3% could be a lot... thanks for your advice, I'll check and recheck

HedgeTrimmer Posted at 4-9 15:31
After little more thought, one concern came to mind.  You mentioned "when I use a white board magnet to try, it could pick it up".  There is possibilty those particular metal decals became magnatized.  Similar to magnetizing tips of screw drivers.

thanks a lot for your input, good point about getting the decal magnetized... I didn't thought of that... not sure if that is valid, but I have tried to put the decals next to and around my iphone with the compass on, there's no affect at all... not sure if that signify anything?

hallmark007 Posted at 4-9 21:45
I see the troll has started up again, maybe show a bit of respect for the OP, and don’t try confuse his issue with BS .

thanks a lot captain.... so nice of you....

fans3eaf9bee Posted at 4-9 23:02
thanks a lot for your input, good point about getting the decal magnetized... I didn't thought of that... not sure if that is valid, but I have tried to put the decals next to and around my iphone with the compass on, there's no affect at all... not sure if that signify anything?

but I have tried to put the decals next to and around my iphone with the compass on, there's no affect at all... not sure if that signify anything?

It would point to drone's compass not being effected.


If you want to test further with your phone (SmartDevice), suggest using one of Free (or nearly Free) iOS or Android OS Apps that allow you to see what your SmartPhone's internal three magnetic field sensors are detecting.  The Apps normally allow you to choose between Gauss or micro-Teslas for display values of sensors.  Apps usually show a combined value for all three sensors, with some Apps allowing you to see individual values for each magnetic field sensors (X,Y,&Z).


Example output from iOS magnetic field strength App, with display set to show combined value of all three sensors.

Field strength is being displayed over time, as running circular chart.  Having no reference to a compass face.




What you are looking for is a change from Earth's normal magnetic field (48.8 uTeslas above).

Change can be either an increase or decrease in selected value.



In above example the outward bumps is Smartdevice passing over metal railing, with inward dip being Smartdevice getting closer to (then further away from) side of metal building.

If you want to try using an such an App to see if an isolated small metal sticker having been previous picked up with a magnetic could effect magnetic field sensors...

You need to do testing away from any other sources of magnetic interference.  Whether it be ferrous metals or electrically generated magnetic field.  Homes usually have lots of sources.


First, make sure you do not have any ferrous metal on you.
Next get XY&Z readings without metal sticker near Smartdevice running App.

Then place metal sticker on Smartdevice in a few different places.

Finally moving metal sticker away.

Any changes to X, Y, or Z sensor readings would indicate metal sticker is having an effect.  Whether that effect is enough to effect drone's compass accuracy is going to depend on changes to Gauss or microTelsas levels from norm.


Best check would have been looking at Magnetic Field Strength levels of drone as reported by GO-4 App, prior to placing metal stickers, then afterwards.  There has been a lot of Pilots state Mavic Air's internal compass (three magnetic field strength sensors) is more senstive than compasses in say Mavic Pro.

HedgeTrimmer Posted at 4-10 00:48
but I have tried to put the decals next to and around my iphone with the compass on, there's no affect at all... not sure if that signify anything?

It would point to drone's compass not being effected.

wow, thanks a lot for your information, that's a lot to learn from..... I guess I need some time to try digest this... or even search for a video to learn... but really, thanks a lot.... I hope I could understand how to apply this test to my MA..

fans3eaf9bee Posted at 4-9 23:03
thanks a lot captain.... so nice of you....

The truth is there are so many metal parts in your drone, that if you just ask yourself why are these not effecting my compass you will get the simple answer.

It because your compass has been calibrated with all of these parts on, so simply adding your decals to your craft will just require a simple compass calibration to bring into line the parameters now of your aircraft.

Regarding other apps , nobody uses them and with good reason, everything you need to inform you of magnetic interference is already on your craft, this is about hobbyists flying their drones not about trying to take off with a rocket.

MavAir is tremendously accurate in picking up magnetic interference as well as changes in  magnetic declination . We see almost no compass problems with MavAir and very few crashes if any at all because craft failed to pickup magnetic interference.

It’s true your craft will Not take off with magnetic interference, so absolutely no need to make things more complicated by using apps which will offer no benefit to you and your enjoyment of flying.

If you were to take all this on board you would most likely get of the ground. So don’t make things more complicated than they need be and go enjoy your craft with its new suit of Armour .

fans3eaf9bee Posted at 4-10 01:22
wow, thanks a lot for your information, that's a lot to learn from..... I guess I need some time to try digest this... or even search for a video to learn... but really, thanks a lot.... I hope I could understand how to apply this test to my MA..

Your welcome.  

Was surprised some of Metal Decals were actually magnetic.  Serious decals!  Most stuff now a days is plastic made to look metal.  

If only Metal Decals had been made of non-ferrous metals.  Like say aluminum or copper which is found in drones.  Copper used for electrical wiring.  Aluminum used for heat-sinks.

All this has got me wondering about how much ferrous metal is in our drones?  (Lot of plastic...)  Have to check out my MPp and see if a 100# magnetic can pick it up.  (Only kidding)  Think I will use one of magnetic field strength Apps on my iPhone instead.

Have you done a flight test or basic hover with drone?

Your Red MA with Ferrai decals does look cool!

hallmark007 Posted at 4-10 01:48
The truth is there are so many metal parts in your drone, that if you just ask yourself why are these not effecting my compass you will get the simple answer.

It because your compass has been calibrated with all of these parts on, so simply adding your decals to your craft will just require a simple compass calibration to bring into line the parameters now of your aircraft.

completely understand, thanks a lot!!

HedgeTrimmer Posted at 4-10 07:25
Your welcome.  

Was surprised some of Metal Decals were actually magnetic.  Serious decals!  Most stuff now a days is plastic made to look metal.  

Thanks, I like the decals too...

I was busy after putting them on, but tried:

1) at home, Atti Mode works perfect
2) night flying at park with street lamp, Atti Mode works perfect
3) night flying at a place I struggle to get GPS, same amount of GPS gained
4) day flying at my usual flying place, 14-15 GPS as usual

Compass calibration needed pretty much as usual amount, flew for a while with no extra calibration required

it seems that it sounds decent to me?

fans3eaf9bee Posted at 4-10 22:16
Thanks, I like the decals too...

I was busy after putting them on, but tried:

Being it is flying well, not slowly rotating as you fly, and not showing problems with compass.  Sounds good.

If compass calibration requests were more than you normally experience, that would be a reason for concern.

Reading here, for some reason Mavic Air's compass (sensors & electronics of) seems to require more compass calibrations than Mavic Pro or Mavic 2 Pro drones.   Usually you can fly in same area with Mavic Pro without any compass calibration nags.  Whereas owners of Mavic Air have reported having to calibrate it's compass prior to each flight.  Granted a few continue to try to launch from ill advise areas, like concrete with steel rebar, which causes compass problems.

One question: How did you get your Mavic Air to fly in ATTI mode?   Didn't know that was selectable option.

HedgeTrimmer Posted at 4-11 07:23
Being it is flying well, not slowly rotating as you fly, and not showing problems with compass.  Sounds good.

If compass calibration requests were more than you normally experience, that would be a reason for concern.

Thanks, actually it sounds pretty normal to me over the past week with a few flight, and no, it did not do silly rotation etc.... so I guess the decals seems fine....

Sorry I may have mis led you, I was flying at the park where I live, a known low GPS signal place, so it was in Atti mode.... and it seems decent....

fans3eaf9bee Posted at 4-8 08:24
Thanks all..... well, i’ve put them on anyway, Will just give it a safe flight check and observe before going wild

I quite like the result at the end

That looks awesome!