Finally it's my Mini's turn - flew straight into a wall and crashed

[slup]

OK, just to make sure that I have really learnt it. I just did an experiment with the (crashed) Mini inside my apartment. I powered it on close to the floor , hovered it and check the yaw360 and magyaw figures in the .DAT file. Then I repeated but with the Mini powered on 1.5 m above the floor. The orientation of the drone was generally the same in the two flights. Here are the results :

View attachment 95421

It is very obvious that powering the drone close to the floor can cause an error of about 180 degrees in yaw360 which I believe is used for position correction during flight.

I must have powered the Mini on close to the floor in today's flight but somewhere else in the previous flights so I got off in the past but not today.

Yeah ... exactly, & out from what you say, one way to push the odds in your favor is to power on in hand followed by hand launch/catch.

 

[Meta4]

Still can't figure out why I got off in the previous flight ( and several others at exactly the same location ).

If your launch point was reinforced concrete (like most similar incidents), this is what you are dealing with:

You can create the problem by launching a couple of feet from a big steel object or with a smaller piece of steel just an inch or two from the drone's compass.
With reinforced concrete, there are plenty of ways to place the drone without the compass being within range of enough steel to cause a problem.
But move it just a couple of inches and the compass might be right on top of a crossing point, or an overlap area where there is more steel.
Reinforced concrete surfaces are not a safe launch spot.

 

[Prismatic]

... everyone needs to understand that both compass errors and magnetic interference to your drone is like a sledge hammer to its brain. Yes it will fly with the initial impact but the swelling is going to happen and it will no longer be able to think straight ...

That analogy is like a broken oar on a basketball court. ?