OK - let’s add some meat to this compass discussion. (It’s taken me an hour to locate a video I took over 4 years ago.)
Back then, when people were having this same compass calibration discussion after each flyaway (very frequently), I carried out a bit of an experiment with my P2.
The compass on the P2 is (should be) mounted on one of the landing-gear legs … and when I changed the rather fragile P2 legs for some more robust carbon fibre ones (that, importantly, also provided better ground clearance for the H33D gimbal), I had to relocate the compass.
Everyone was saying I HAD to recalibrate it! So, this got me interested to find out what would happen if I didn’t. And it flew without an issue.
I became more intrigued … so I undid the cable-tie used to hold the compass onto the bracket on the leg, so that it was dangling totally free …. AND out of the alignment it held when on the previous, and new, legs … and wobbling about in the downdraft.
Again, it flew … without an issue … and hovered as accurately as it ever did. (Video below.)
I tried RTH, and it flew straight to me over a distance of about 400m (the size of the field - RTH height set to 5m - so if it went off at a tangent I’d see which bushes/trees it went into).
Whilst I don’t have video of the RTH exercise (I wanted to hold the controller just in case!), I do have video of it hovering, below, on quite a windy spring day.
The dangling compass is marked in this frame-grab, and as it should be fixed in the other two photos that I’ve just taken.
Video:
Note, also, powerlines in the background that I’ve flown VERY close to - specifically to find out if it affected the P2’s stability or compass.