Having owned my P3S for 3 weeks I finally got to fly it for the first time today due to poor weather. But takeoff had an unexpected issue which I'm trying to understand.

So I'm in the middle of nowhere away from trees and buildings etc. I calibrated the GPS before takeoff and then started the motors. As soon as I lifted off the ground the phantom surged sideways at speed before clipping the grass and flipping it over onto its back. After this unusual start it worked fine for the following half hour. The only thing I can think caused the issue is that I took off next to a wood table and bench which had metal legs. Could this have caused the unusual behaviour?

Anyway no harm done but don't want to repeat it!

No-one has ever calibrated the GPS in a Phantom.
You have confused GPS with compass.
If you calibrated and launched from a position close to a lot of steel that may have caused a problem.
Best to brush up on compass issues - understanding helps you to fly with less problems.
http://www.phantompilots.com/thr ... plete-primer.32829/

Hi , Data Ghost
That's really terrible . Please find some wild place away from  metal environment and give another try . Remember to do the Compass Calibration before flight .  

u sure u didnt mix up the props?

Thanks for your replies, and yes I meant compass not GPS sorry.  Also thanks for the link.  Aside from that it all went very smoothly, kept it in beginner mode and took it slow.  These are the results, bit boring I admit, but got to start somewhere: