Had my first ever flyaway today

[msinger]

Only ferrous metals are the problem

Indeed. Or magnetic metals for those who cannot spot ferrous metals with their eyes.

But, more importantly, some cars have glass, canvas, and other materials on top. Hence my question.

 

[KB9Radio]

Ok so I was at Loch Katrine in Scotland doing a bit of filming and it all went well. No issue's, the drone performed as it should. On the way home I was going over an area known as Dukes pass and thought I'd stop and get some pics of a distant Loch. So set the drone up, waited for GPS lock and took off. I only wanted to go straight up to around 50m. As I got to around 40m the drone which was in normal mode suddenly shot off sideways in what seemed like sports mode. It wouldn't respond to my control inputs. It done this for maybe 6-10 seconds before it responded to the controls and stopped. Needless to say I brought it straight back down. I took off from the roof of my car so not sure if that had any effect and did notice it drifting to the left just after take off. I've taken off from the roof before without any issues. I only do that if there's no decent take off spot.
Drone is a mini 2.

I never take off from a metal surface, or anything that probably contains steel such as concrete. Pick yourself up a foldable (portable) landing/takeoff pad, and save yourself a lot of problems. Your pretty lucky you got control of it and landed, usually they keep going till they slam into something.

 

[KB9Radio]

It may have not been the roof. I've launched and landed quite a few times from the roof of my Subaru Outback without problems with compass bias. There's no sunroof with a motor and I think the roof is aluminum. It's definitely advisable to confirm the compass reading prior to beginning each flight.

Aluminum is not magnetic and wouldn't affect it. Most others are steel of some sort.

 

[rmcelrath]

The drone behavior you described directly after take-off-drifting to the left. When I first bought my mini2 I experienced similar behavior during one of he first flights. (Takeoff was from a level spot on the ground.) I kept it in a hover, but the drifting behavior continued. I landed it immediately, restarted the app/controller and the drone.
Took off again and did some simple flight control checks to assure the drone was responding correctly and would return to a stable hover. It did, so I continued with the flight. I would politely recommend a quick but thorough flight control input and stable hover check each time you fly, as well (as you mentioned) assuring ample GPS sat reception and the updated home point.

It took you longer to read all that, than it does to accomplish, so it's easy, and can help identify/prevent these type of events. As good as DJI drone hardware/software is, it's not perfect and can hiccup occasionally. My .02.
R McElrath
mini2
Mavic3

 

[RangerEd]

Thanks for the replies everybody. I'm going to put it down to the roof. I have used the roof of the car to take off a few times but do try to avoid it if I can. When I got home I calibrated the compass & IMU and have flown it since with no issues.

I typically fly where there's no solid ground so I've gotten pretty good at taking off and landing using my hand. I started using a pair of gloves but I don't even use it now. Just put your palm out, let it land and wait for the props to stop spinning. Don't try to grab it as some videos suggest; that can lead to a mis-grab and you can end up with cut fingers.

 

[Jamesz]

It's probably not relevant to dwell on what the roof is made of in relation to probable magnetic issues with this flight- you can't ignore the engine, transmission, body panels, suspension members....
Taking off close to more than a ton of steel is asking for trouble.

 

[MAvic_South_Oz]

Most roofs of autos aren't aluminium / aluminum, and even if so, the internal braces might be mild or high strength steel.
Tesla X models are one of the only one in their range all aluminium, expect for some of the chassis system, but there are more mainstream vehicles coming along like the Ford F150 that do have an aluminium roof.
Just grab a magnet and check your panels, will not be attracted if aluminium.

Still, get into good habits.
Wherever / whenever taking off, if you acquire GPS signal and home point registers BEFORE taking off, you will either get a warning if something is off with magnetic interference, AND you should always check the drone alignment matches to the map orientation when asked by the DJI lady to 'please check it on the map'.

 

[MasterYeti]

Remember that although DJI drones are very good at knowing where they are etc when you turn them on it becomes a bad habit to rely on the settings always being accurate and just put it straight into the sky. That is why they give you a calibrate option in the app. It is always a good idea to take 5 minutes and recalibrate occasionally, especially if you are flying in an area you don't normally frequent.

 

[Meta4]

It is always a good idea to take 5 minutes and recalibrate occasionally, especially if you are flying in an area you don't normally frequent.

That's just an old myth and recalibrating things won't make your flying any safer.
There is no need to recalibrate your compass or IMU before flight and it doesn't matter if you are flying in your backyard or 10,000 miles from home.
It's a better idea to learn how your drone actually works.
Read the first post in this thread to find out what compass calibration actually does and when it might be necessary (almost never).

A short explanation of compass function, calibration and errors.

BACKGROUND The aircraft compass is often misunderstood, both in terms of function and purpose, but it is important to understand what the compass measures, why, and what happens to that information. At the most basic level the purpose of the compass is to measure the earth’s magnetic field in...

mavicpilots.com

 

[MasterYeti]

That's just an old myth and recalibrating things won't make your flying any safer.
There is no need to recalibrate your compass or IMU before flight and it doesn't matter if you are flying in your backyard or 10,000 miles from home.
It's a better idea to learn how your drone actually works.
Read the first post in this thread to find out what compass calibration actually does and when it might be necessary (almost never).

A short explanation of compass function, calibration and errors.

BACKGROUND The aircraft compass is often misunderstood, both in terms of function and purpose, but it is important to understand what the compass measures, why, and what happens to that information. At the most basic level the purpose of the compass is to measure the earth’s magnetic field in...

mavicpilots.com

Thank you for that Meta4 however if you read my post clearly I said occasionally. With DJI that would normally be if the drone tells you it needs doing or if it is behaving in non-standard manner. Clearly a drone deciding to take off in a random direction I would say is non-standard behaviour.
The post you reference is an extremely interesting read (and I have read it all) but only relevant to compass calibration which is the old spin it a couple of times flat and then spin again on end and in that I agree with you that the DJI drones would rarely if ever need the compass calibrating as they store the settings (notice I did not say never though). On lower model drones that do not store the compass settings you generally have to calibrate every time they are powered up which is a real grind. DJI and other top brand devices however have far more sensors than just a compass that should all be in tune so the "occasional" check yourself process I do not think a bad thing.
If you choose not to recalibrate your device/s then that is up to you but taking a stance that a calibrated device will never need calibrating again I believe is remiss, especially when the said item is portable, gets bounced around and the developer builds this exact functionality into the software.

 

[Meta4]

Thank you for that Meta4 however if you read my post clearly I said occasionally. With DJI that would normally be if the drone tells you it needs doing or if it is behaving in non-standard manner.

If you think your drone is telling you to recalibrate the compass, it's probably not necessary.
If you place your drone somewhere that the compass detects magnetic interference, DJI's warning message tells you to recalibrate the compass, but that will never fix the problem that the compass is warning about.
Powering off, moving away from the problem and starting again is the correct action.
And these situations account for something like 99% of the times that the app warns to recalibrate the compass

Clearly a drone deciding to take off in a random direction I would say is non-standard behaviour.

If your drone takes off in a random direction, that is a usually an indication that the problem was caused by a yaw error.
And that's something that recalibrating the compass won't "fix" either.

 

[Daytona500]

and the OP still hasn't posted his data, and probably won't so we'll never know what really happened

 

[RodPad]

Hello,

MasterYeti

mavicpilots.com

I didn't believe: Meta4 comments on this compass stuff before Mavic's existed. I kept reading his posts helping others figure out what happened and many times they found it.

Anyways, we don't what your flying? Nothing in your signature. It would be great if you signed in to: Pilot Check In

We are all waiting for the OP to share some data, I will sit back.

Rod.

 

[Starz]

We are all waiting for the OP to share some data

Not me. I know better.

 

[Coconut Island Drones]

I'm working 12 and half hours shifts at the moment and simply haven't got the time to find the data. Finding the data is going to be a challenge for me so once I work out how to do it I will. I can only apologise.

 

[RodPad]

Threads get long and confusing.
I assume he didn't loose his drone?

If this is the case.

Coconut Island Drones

mavicpilots.com

Update us a needed, we need to put this thread on idol.

Rod..

 

[Robert Prior]

It's worth verifying the compass reading, along with the home point, before each flight.

I always do that as soon as the nice lady says "The home point has been updated. Please check it on the map." I figure she knows what she's talking about.

 

[Meta4]

Finding the data is going to be a challenge for me so once I work out how to do it I will.

Post #14 contains instructions.
The process takes just a couple of minutes.

 

[MS Coast]

I always do that as soon as the nice lady says "The home point has been updated. Please check it on the map." I figure she knows what she's talking about.

It's better to check the compass before taking off. If the compass is biased and the drone is airborne, you may have a problem. If still on the ground, there's none. Just shut down, move a bit, and try again.

 

[MAvic_South_Oz]

It's better to check the compass before taking off. If the compass is biased and the drone is airborne, you may have a problem. If still on the ground, there's none. Just shut down, move a bit, and try again.

Exactly, better to get GPS locked first, and check it on the map . . . even before starting the motors.
This is usually fast enough for me to get that while doing start up settings checks, last minute site check, etc.

If the anomaly of compass / IMU disagreement is present and you take off first before GPS lock and map alignment check, it's pretty much game over for a flyaway.