"ok, this is a new test flight.

Now I can see the behaviour of throttle dropping when switching flight modes while flying. Still haven't found the fix for this. It is not consistent though. You may see that in the last switch modes from the…"

"hi Michael, I've connected APM Planner and watched live the graphs changing flight modes on the RC, I'm not seeing that throttle is dropping when testing this way. I've uploaded screenshot.Screenshot 2016-08-12 21.55.15.png"

"Thanks Mike. Battery was low indeed for this test, but I did more tests with full battery and noticed same behaviour when changing flight modes.

Is there any parameter that sets throttle value when changing flight modes?"

"Thanks Michael. I'm attaching here log file. 16-08-10_17-27-02.bin"

"thanks David.

I've tested between ALT HOLD and LOITER.
I've set the throttle to 50% near ground but flying in ALT HOLD, switched to LOITER and copter drops completely to ground as there would be not throttle set at all. "

"thnks for sharing!"

"Bill, Dax
thank you so much for taking the time to answer! 
will take note of all the advices. 

I did found a screw falling of from the inside, but can't tell if it was loose before or after crash.
Do you think the lack of some of the vibration…"

"Thank you Bill for your help. 

So I've read about vibrations in http://copter.ardupilot.com/wiki/common-diagnosing-problems-using-l...
Is there anything else I can read to understand more?

Can we assume that the 70m crash heigh is because the baro…"

"Thank you very much Dax!"

"thanks Dax 

Having that parameter set and the flight mode in stabilize mode, will it stop spinning even though it is still not on ground? (altitude above 0)"

"So, I was reading the documentation regarding follow me, it states:
"

Warning: Like all other modes in which the autopilot is responsible for altitude hold (Loiter, AltHold), the barometer is used in the altitude calculation meaning that it can…"