this is what happened to me.. be CAREFUL

[ArranEye]

It's surprising how little metal can affect the compass in your MP. Prior to taking mine out for it's first test flights I was checking it out at home, with it sitting on a glass-topped table. A 3-inch metal disk attaching the glass plate to the table leg was sufficient to throw the compass calibration right off the scale.

 

[m0j0]

guys what happened is really "crazy"..
in few lines:
1) turned on the drone..
2) wait for GPS.. i check compass and imu if they are just fine..

Add this tip - when you check your sensors do it off the ground. My first flight at a location I usually starts with a few checks. I launch and let it hover at a safe height. I watch and ensure that the hover is locked in and that there is no drift. Then I check the sensors. After checking the sensors I fly out in a straight line and then back. Making sure that there is no arc in the flight path. If there is an ARC I won't fly the location. That happened once with a P3.

3)since I'm a newbie I check and over check the area I wanna fly..!

What are you checking for? At the top of your list you should put magnetic interference as something to check for.. launching from areas with metal is an absolute bad idea. Car hood, reinforced concrete that big hunk of steel in your photo are all terrible launch location choices.

4) ready i fly.. all good and 5 seconds later drone goes 100% crazy!!

You initialized your Mavic in an area of magnetic interference. Then flew away from it which caused the problem.

!
do NOT take off from anything metallic.. don't or you might be not same lucky!

Well this warning belongs first it is the root cause of the problem.