This has happened with my P4A and the Mavic Pro Plat that i fly, everything checks out prior to flight. Green across the board.
Here is the issue i have, if i take off too fast and go in a direction at the same time i get a compass error, the RPA then goes either beserk or into ATTI mode.
I am now used to flying without GPS (practice over the years) so its no longer scary as it was back when i first started flying. Still gets the blood pumping as you try and get a $2000 flying device back and landed without destroying it or someone.

That sounds like a problem with your takeoff location.
Let me guess .... you're launching from a reinforced concrete surface?

Labroides Posted at 2-18 16:04
That sounds like a problem with your takeoff location.
Let me guess .... you're launching from a reinforced concrete surface?

Yeah i have it inside a metal cage! Come on mate.
Take off location change and is never the same.

DarkZero Posted at 2-18 16:11
Yeah i have it inside a metal cage! Come on mate.
Take off location change and is never the same.

Well .. you gave no details and people report similar incidents every week after launching from their driveway or sidewalk.
Your details are sketchy.
A more detailed explanation and actual flight data would be required to see what's going on.

"here is the issue i have, if i take off too fast and go in a direction at the same time i get a compass error, the RPA then goes either beserk or into ATTI mode"

Kinda hard to figure that out.  

Labroides Posted at 2-18 16:35
Well .. you gave no details and people report similar incidents every week after launching from their driveway or sidewalk.
Your details are sketchy.
A more detailed explanation and actual flight data would be required to see what's going on.

Opening with "Let me guess..." is a pretty condescending reply. Anyway moving on, I take off from grass or natural ground. Rarely from anything man made. It only happens when i take off fast. If i go slow or normal it doesn't happen.

Go slower.....problem solved!

DarkZero Posted at 2-18 16:43
Opening with "Let me guess..." is a pretty condescending reply. Anyway moving on, I take off from grass or natural ground. Rarely from anything man made. It only happens when i take off fast. If i go slow or normal it doesn't happen.

Opening with "Let me guess..." is a pretty condescending reply.
I see similar reports every week and after looking into the data, what shows as the cause is almost always launching from reinforced concrete or very close to some magnetic interference.
If you're case is different, it's unusual.
Seeing flight data would be helpful to work out what's going on.

Anyway moving on, I take off from grass or natural ground. Rarely from anything man made. It only happens when i take off fast. If i go slow or normal it doesn't happen.
The speed that you fly off at should have no effect on compass issues.
If your Phantom was rotating very fast maybe, but not for straight line flying.