I am flying a Phantom 3 Pro with the latest firmware (1.1.9) and had an issue on my last flight.

I calibrated the compass and had safe to fly GPS before I took off. Everything was going smoothly until all of a sudden, the green "safe to fly" GPS bar on my iPad turned red and said something to the affect of "compass error." At this time, the drone started drifting off in a random direction, but since it was directly over me, it wasn't hard for me to easily take control and guide it back to me and land...

When the drone got closer to the ground, the error disapeared and the iPad once again showed "safe to fly GPS." I continued flying it for several more minutes and didn't have an issue.

Is there anyway I can figure out happened? No harm no foul but still... it could have been bad if it had been further away from me.

Yep. this has happened to more and more folks. Very alarming.

Keep in mind this isn't a "Fly-away". When this compass error occurs - this is the quad automatically switching to Atti mode (vs GPS) so it begins to be pushed by the wind at that altitude. This is normal behavior when in ATTI so I guess it could more accurately be described as a "Float-away."

That said, this can be scary and dangeruos without a clear line of sight. Personally I think the next firmware update needs to do something in regard to this more commonly occuring event.

See my post about the same thing....
http://forum.dji.com/thread-17267-1-1.html

In my experience the compass issue is due to a BAD compass calibration. No, I don't mean you do it incorrectly, I mean the data it saves as a calibration is BAD. This can happen for many reasons like having ferrous material near the Phantom whilst calibrating ( this includes the controller itself, phone in pockets, keys, belt buckle, re-bar in the ground and anything else ferrous near it when calibrating. The reason it gives the error when a few feet up in that air is because it becomes FREE of whatever forces were upon it when calibrating and this "throws" its compass info off and it shows an error.

Like mentioned above, the "flyaway" feeling you got was due to the P3 popping to Atti and drifting because of the wind.

I plan to make a video demonstrating my theory soon as people really need to understand the issue and why it happens. yes there is a "small" chance this is a bad compass but in most cases its just the P3 being fed bad compass readings on the ground.

I use an app called Multi Measure 2 ( https://itunes.apple.com/gb/app/ ... ll-in-1/id933528345 ) and scout the location I plan to launch/calibrate beforehand for fluctuations in magnetic readings. if the app shows a difference between ground and 7 feet up then I dont calibrate there.
I really cant think what DJI can do to "fix" this as in order to make the P3 more stable and fly true they have upgraded the compass, this made it more sensitive. Its not a bad thing it just means that more thought needs to be put into flying it. Also, unless you move about 100 miles from last flying location, don't do a compass calibration. if you get a really good one in the middle of a nice green field, dont ruin it with anohter from a location ful of metal.

You can now buy the official DJI Hardshell Backpack

Remember to buy extra propellers and one or two spare batteries to keep you flying

www.Phantom-Guide.co.uk - The Ultimate Phantom 3 Resource

Thanks for the info guys. I didn't realize you didn't have to calibrate within 100 miles.. I thought it was more like 10 miles.

Great info thanks for sharing.

Today I got my first compass errors in the middle of the flight, and it was not restored. I had to take it back and land in ATTI mode. It was a little bit nervous when it blew a Little. I calibrated the compass and gave me out on three new flights without problems. Just a reminder of how important  it is to always have the bird in sight, it makes life so much easier when the autopilot fails.

PS: I run on firmware 1.1.8

And when there is a strong magnetic interference source in the flight environment, the compass will be interferenced and the flight mode will jump from P-GPS to P-ATTI.

Not sure if this has anything to do with it but on the 9th and 10th we have had lots of solar x-ray activity. My monitor on my phone stated it was "stormy" which is the highest level.

This is exactly what happened to my P3 advanced last Friday and that was my 2nd flight of P3! The first flight was smooth and I was able to flew my P3 up to about 100 feet and took a good 360 degree video. The next day, I wanted to show my wife how to fly the P3 in my backyard where the first flight took place the day before. It occurred that I have to calibrate the compass twice. Nevertheless the apps shows green and okay to fly. So the P3 went up to about 80 feet and hovered for a couple of minutes. Suddenly it drifted at high speed in a straight line. It was kind of panic at that moment but I was able to control it descend to my neighbor's backyard, but the P3 was somehow crash-landed and the propellers were damaged. The rotors appear to be okay and camera still working. I noticed from the flight record in my iPad that the GPS was switch to ATTI when it started flying away. I remember the GPS signal was showing 8 satellites, typically I would see about 12-15. I didn't see the message of "compass error" although it might appear when it started to fly away but I was probably too panic to see that message. I was puzzled that there was no wind that day and if P3 was flying at ATTI mode, the drifting should not caused by the wind but something else. I also saw that the home point was set correctly in my backyard so it must not be the reason someone else raised in the past that if the home point is not correctly set, phantom might fly towad an incorrect home point if the connection was lost. I believe my controller had a good connection to P3.

Later I got in touch with DJI online support. the guy online examined my flight record and was talking that there was some interference of GPS and compass which causes the fly-away. It looks like DJI is aware of this issue and they recommended me get a RMA number and ship my P3 for repair in their LA site.

but I noticed that on 5/22/2015 DJI released a new firmware which seems to address the compass issue..
https://www.dji.com/info/releases/phantom-3-v1-1-9

Major Updates：

1. Fixed issue of some aircraft unable to determine their altitudes.

2. Fixed issue of the DJI Pilot app unable to obtain and display battery error history.

3. Fixed issue of the compass calibration progress not being displayed properly.

Ive had same problem twice 5 flights.   scared to fly it now.   The first time was after not having flow for over a week.   It took off when was 120 or so feet in the air and went nearly 500 feet away I think.    I thought for sure  I was going to lose it.   Thankfully  after it got out of range it went into GO HOME mode and flew back.  I updated all my software and flew again for 3 minutes with success
Tonight 8/12/15 I flew it successfully 250 in the air, and 350ish feet away.  Then I noticed my RC firmware needed to be updated.   I updated it, then flew it again.   It started to float  away and I had a compass error.    pretty scary but luckly I was only about 80 feet and I crash landed it into a parking lot.   I took it home then recalibrated the compass.   It flew OK...but man am I nervous to fly this think anywhere now.   

This all started happening after the latest few updates....frustrating!

I had my first flight to day and got an compass error. nothing strange happened. I could land very easy. i have the latest firmware. 1.4.010

sploodge Posted at 2015-6-7 10:31
In my experience the compass issue is due to a BAD compass calibration. No, I don't mean you do it i ...

Thank you, sploodge.  I am a newbie trying to get this right.  I had always been recalibrating compass every time I flew in a different location than last time.
Today, i had a compass  error that I would like to figure out.  I was going to try to fly in a downtown area for a particular shot, so I went before sunrise and set up, calibrating successfully. As soon I as got up about 10 feet, I got a compass error, and my phantom 3 pro started to drift badly.  I brought it right back down, tried again to calibrate, and it never succeeded.  Do you think this is an unflyable location?  All I want to do is fly straight up, filming the front of a building from about 6 ft away,, and then back down filming as well.