I had just taken off when I noticed it drifting slightly so I was about to bring it back down to land. Next thing I heard "ATTI mode" and it was off, gathering speed and not responding to controls. I watched the neighbours garden zoom past and switched it into Sport mode hoping that would give me more power to fight my way back - I don't really know what I hoped, but I didn't know what to try. This seemed to help and at this point the Spark came back under control and I was able to land it safely. Looking at the logs it appears to have gone back into GPS mode before I switched to Sport so this might have nothing to do with it.

It was a very scarey few seconds and I thought I had lost my Spark. I was very lucky that I regained control so quickly and it was so close to me when it happened.

I took it out again just now and it was fine, but I've really lost confidence in it. I couldn't wait to get it back on the ground.

Log files below if anyone is interested. Wierd to see how it accelerated out of control - I think I now understand what other people say about it zooming off like a rocket!

http://www.phantomhelp.com/LogVi ... Q4AXPRVMDJ/?fref=gc

I also had the same YAW error in my log. See my post in this forum. I'm waiting for a DJI answer before I fly it again.

Looks like a "normal" compass strong interference behaviour, maybe something on the place the drone are flying caused this. The drone quickly come back to GPS mode when interference is gone and you regain controll over it ( the drone are away from the place the interference starts).

This happens to me once with my old parrot bebop, i take off from a interference place, the drone start to drift a little and take it way to the left at full speed until it hits a wall ( believe or not, its the "normal" behaviour when are in strong magnetic place)

Spark looks like to be a very very sensitive to magnetic interference. One incident like this makes us to have 0% confidence on drone.

Sorry to read on it, please contact the Support, provide them with the data and request a data analysis to check what happened. http://www.dji.com/support

I'm wondering if a scan of the area wi-fi should be done prior to flight.  I have an app that scans and tells me for instance 16 networks are broadcasting at different percentages right here at my living room.  What if where I planned to fly there were say 50?  How high would you need to fly to be out of range of home networks?