Parrot anafi magnetic perturbations / crash

Owners_ · Feb 8, 2021

I crashed my anafi for the first time the other day, as far as crashes go I got very lucky. It was between 300 and 400ft up, not unusual height for me, and it had been up for about 10 minutes, when it started going wild tilting and spinning uncontrollably. It DID hold on though and I was able to fight it down pretty close to the ground before losing control.

Once I got to it I immediately noticed one of the front right propellers was gone, and I couldn't find it so I'm not sure if it lost that in the air or just threw it into the snow on landing upside down.
The whole time it was going crazy it showed a message on screen saying "magnetic perturbations". Now that I have recovered it, replaced some propellers, re-attached the gimbal wire that came undone, it is still giving this message. Could somebody please help me to understand what this means? Also if that is what caused my loss of control? I think it threw a propeller in the air and that's what caused the loss of control but I don't know if it would just fall out of the sky from that.

Also on a related note, I pre ordered the anafi when it first came out and have never changed the propellers up until now. How often should the propellers be replaced for safety?

I tried to add the crash video but it's too big and won't load-- I'll link to it on YouTube

I narrowly missed burying it in the snow and I think I got lucky

ParrotAnafiFan · Feb 8, 2021

I received this error before taking off at the same spot on the ground after changing cold batteries, it disappeared and was able to hand launch and normal flight after. Were you holding your phone close to the drone?

I would recalibrate drone again in the middle of no where. Saw this on another site

-When you calibrate your compass, it takes into consideration all the surrounding drone magnetic interference. So when you calibrate your compass in an area with high magnetic interference, this will lead to incorrect compass data

So give it a good clean calibrate away from populated areas, maybe updates causes this.

and dont do it near/on top of your phone and SC3 like this video! They have a field as well.

Phantogram · Feb 8, 2021

I also have this warning more frequently than in the past, also in areas where I didn't have this issue before. It didn't crash the bird, however. Is the latest firmware known to be more susceptible for this?

ParrotAnafiFan · Feb 8, 2021

We think that after updates drone may need it and maybe controller. Or if they improved the compass or something it would make sense.

I am going to re cal drone and prob controller after every drone update now

Owners_ · Feb 8, 2021

parrotanafifan said:
I received this error before taking off at the same spot on the ground after changing cold batteries, it disappeared and was able to hand launch and normal flight after. Were you holding your phone close to the drone?

I would recalibrate drone again in the middle of no where. Saw this on another site

-When you calibrate your compass, it takes into consideration all the surrounding drone magnetic interference. So when you calibrate your compass in an area with high magnetic interference, this will lead to incorrect compass data

So give it a good clean calibrate away from populated areas, maybe updates causes this.

and dont do it near/on top of your phone and SC3 like this video! They have a field as well.

So this is not an error that would make it lose control? I have been scared to take it up high again, but it seems to take off and hover alright. Also, I'm next to a corn field, how far away from everything else do you think I should get? The last time I calibrated was in my basement and I was close to it

ParrotAnafiFan · Feb 8, 2021

Basement. That's probably why. You should always calibrate clean outdoors away form buildings and magnetic interference.

ParrotAnafiFan · Feb 8, 2021

Guys what about flying location though magnetic metals such as Iron in the ground. Can this bother Anafi?

Owners_ · Feb 8, 2021

parrotanafifan said:
Basement. That's probably why. You should always calibrate clean outdoors away form buildings and magnetic interference.

I can manage that. But do you have Any advice on the propellers? I never even thought about changing them before because it's never done anything to noticeably damage them, but I guess they wear out after so long just from normal wear and tear. Also, should I get more oem's or are there better ones for it out there?

Joe_Scot · Feb 8, 2021

I first changed my props after 237 flights (47 hours flying). Maybe I was lucky as I've seen people frequently recommending changing them more often. I had found some tiny cracks in the hubs of 2 props after all that time, though it required a magnifying glass to see that when they were attached to the drone.

I have only used Parrot props as I don't think it's worth trying to save a few quid / dollars on something that is so important.

Owners_ · Feb 8, 2021

Joe_Scot said:
I first changed my props after 237 flights (47 hours flying). Maybe I was lucky as I've seen people frequently recommending changing them more often. I had found some tiny cracks in the hubs of 2 props after all that time, though it required a magnifying glass to see that when they were attached to the drone.

I have only used Parrot props as I don't think it's worth trying to save a few quid / dollars on something that is so important.

I know for other brands at least there are third party props that are supposed to be quieter and more efficient. I am not looking to save money, just didn't know if there was something better performing out there that I haven't seen

BRC · Feb 8, 2021

Owners_ said:
I know for other brands at least there are third party props that are supposed to be quieter and more efficient. I am not looking to save money, just didn't know if there was something better performing out there that I haven't seen

Joe_Scot said:
I first changed my props after 237 flights (47 hours flying). Maybe I was lucky as I've seen people frequently recommending changing them more often. I had found some tiny cracks in the hubs of 2 props after all that time, though it required a magnifying glass to see that when they were attached to the drone.

I have only used Parrot props as I don't think it's worth trying to save a few quid / dollars on something that is so important.

Like Joe Scott I also change props around 50 hours unless I notice nicks etc, during inspection,s and only use OEM,

BRC · Feb 8, 2021

parrotanafifan said:
Guys what about flying location though magnetic metals such as Iron in the ground. Can this bother Anafi?

Yes, I have magnetic perturbations while taking off from concrete driveway.
Same driveway I have used for past year without issue
This error was introduced a few FW releases ago when they changed the way satellites were being acquired
Not an issue for me I just moved drone to grass and use a landing pad

AnafiPilot1 · Feb 9, 2021

They made changes since FF6 6.7.0 to create extra warnings and critical errors from the magnetic sensors on the Anafi.

I think the new warning message has been set to be too sensitive. I have got them in two places where I never got any warnings before.

MustangPhil · Feb 9, 2021

Your problem was certainly more a problem due to the loss of a propeller than from a magnetic interference.

After the loss of a propeller, the wild tilting and the spinning you describe is typical of a drone that tries to stay in the air with 3 props only instead of 4.
One more info that let think that a prop is the root cause is you were flying high away from interferences.

Magnetic interferences do generally happen in the first few feet above the ground or near ‘very strong interferences due to objects’ like metallic frame reinforced concrete, electric wires or poles, bridges (that are a mixture of all problems because of their materials and they generally enclose electric wires to transport energy on the other side of the bank).

I had (and documented on this forum) a few problems with drifting due to magnetic interferences :

- Flying near a brick barbecue that was reinforced with a metallic frame in my garden (slow drift of the Anafi till it crashed on the BBQ). The test with the magnetic compass shows no interference 2 meters above the BBQ but 180° error on the take-off zone...
- Taking off from a wooden bench near a forest. Impossible to land properly, ‘jumped’ all over the place. Found the bench was build of wood... over a metallic structure... (If you search, it is also documented on a thread here)
- Tried to take-off from my car roof (but before, checked it with a hand held magnetic compass). Found the roof top of a car is a magnetic mess... never take off from the roof or the hood of a car, nor calibrate your drone in the car ‘because it’s cold and windy outside’. Also a thread on it here.
- With a Phantom 4... software did refuse to take-off due to high magnetic interferences (I was on a parking lot with trucks dedicated portions of reinforced concrete, surely with metal, confirmed with a compass).

The error message you got was probably induced by the intensive warbling of your Anafi when it lost the prop plus the fact you did the calibration in your basement. But appart from the message, the spinning is only due to the loss of the prop.

Calibration of a drone = calibration of the magnetometer = Indicate your drone a zone where the magnetic field is ‘Ok’ in your vicinity to let it know when a difference can be due to an object (hard iron effect).

When is the magnetic field OK ? That’s when you handheld magnetic compass (the real one for hiking, not the simulation in your phone) Indicates ‘roughly’ the north When ‘on the ground’ and when you move 1 or 2 meters above the ground, it still gives you the same direction...

Hope this helps

Owners_ · Feb 9, 2021

MustangPhil said:
Your problem was certainly more a problem due to the loss of a propeller than from a magnetic interference.

After the loss of a propeller, the wild tilting and the spinning you describe is typical of a drone that tries to stay in the air with 3 props only instead of 4.
One more info that let think that a prop is the root cause is you were flying high away from interferences.

Magnetic interferences do generally happen in the first few feet above the ground or near ‘very strong interferences due to objects’ like metallic frame reinforced concrete, electric wires or poles, bridges (that are a mixture of all problems because of their materials and they generally enclose electric wires to transport energy on the other side of the bank).

I had (and documented on this forum) a few problems with drifting due to magnetic interferences :

- Flying near a brick barbecue that was reinforced with a metallic frame in my garden (slow drift of the Anafi till it crashed on the BBQ). The test with the magnetic compass shows no interference 2 meters above the BBQ but 180° error on the take-off zone...
- Taking off from a wooden bench near a forest. Impossible to land properly, ‘jumped’ all over the place. Found the bench was build of wood... over a metallic structure... (If you search, it is also documented on a thread here)
- Tried to take-off from my car roof (but before, checked it with a hand held magnetic compass). Found the roof top of a car is a magnetic mess... never take off from the roof or the hood of a car, nor calibrate your drone in the car ‘because it’s cold and windy outside’. Also a thread on it here.
- With a Phantom 4... software did refuse to take-off due to high magnetic interferences (I was on a parking lot with trucks dedicated portions of reinforced concrete, surely with metal, confirmed with a compass).

The error message you got was probably induced by the intensive warbling of your Anafi when it lost the prop plus the fact you did the calibration in your basement. But appart from the message, the spinning is only due to the loss of the prop.

Calibration of a drone = calibration of the magnetometer = Indicate your drone a zone where the magnetic field is ‘Ok’ in your vicinity to let it know when a difference can be due to an object (hard iron effect).

When is the magnetic field OK ? That’s when you handheld magnetic compass (the real one for hiking, not the simulation in your phone) Indicates ‘roughly’ the north When ‘on the ground’ and when you move 1 or 2 meters above the ground, it still gives you the same direction...

Hope this helps

Thank you for the information! I needed some reassurance that the calibration didn't cause the crash. When I calibrated it in the basement it was after the crash and I don't remember the last time it needed it before that.

MustangPhil · Feb 9, 2021

Just don't forget to re-calibrate it next time you go fly outside... Basement calibration is definitly not a good idea ;0)

ParrotAnafiFan · Feb 9, 2021

I disagree. i was flying in an open field with no buildings around for miles amd still getting that magnetic message. I was flying around ground that had a lot of Iron in it. This means either needed calibration after updates or ground was effecting it.

Don't calibrate on rocks, the ground or near cars either.

Moskitaba · Feb 14, 2021

Owners_ said:
Once I got to it I immediately noticed one of the front right propellers was gone, ...

Well, good news that anafi could land back without major damage with a missing propeller!
I had the problem once at take-off: anafi on ground, I pressed "take-off", motors started and stopped immediately with an error message (I don't remember which one).
One of the propellers was near anafi, on ground, with the screw!
I mounted it again, verified all propellers screws and could fly normally.
So, it's important to check the propellers screws regularly. Adding locking glue could also be a good idea.

ParrotAnafiFan · Feb 14, 2021

Moskitaba said:
Well, good news that anafi could land back without major damage with a missing propeller!
I had the problem once at take-off: anafi on ground, I pressed "take-off", motors started and stopped immediately with an error message (I don't remember which one).
One of the propellers was near anafi, on ground, with the screw!
I mounted it again, verified all propellers screws and could fly normally.
So, it's important to check the propellers screws regularly. Adding locking glue could also be a good idea.

so your saying anafi made it back with 1 missing or both blades missing on 1 motor?