This morning I did a maiden flight of my latest Y6 build. It has a Cube Orange running Copter 4.0.7 & a Here2.
At the end of the final flight, I landed the copter in loiter mode & immediately began holding the left stick (mode 2 radio) fully down & to the left to disarm. However instead of the motors dropping to their idle speed & then disarming, they remained at a heightened speed. About 4 seconds later, still with the left stick held fully down & left, the motors sped up & the copter lifted off the ground & rotated slightly to the left (presumably because I was holding left rudder). A fraction of a second later the copter seemed to come to its senses, landed again & this time the motors did drop to their idle speed & disarmed.
I had a GoPro attached to the copter at the time, so here is the video evidence -
I have uploaded the log file here (the incident happens at the very end) -
I have looked at the logs & RC3 (throttle) does spike high at that time. My radio setup is a FrSky Taranis X-Lite Pro with a R9M Lite Pro module connecting to a R9MM receiver over 868MHz. All radio firmwares are up to date & I have never encountered (or heard of anybody else encountering) false channel values with this setup before. I recalibrated the radio when I arrived home & the max/min/trim values did not change at all.
The other potentially pertinent piece of information is that I was struggling with bad compass variance between the Cube compass & the Here2 compass the whole time. I recalibrated several times while in the field, but could not solve the issue. Since arriving home I think I have potentially solved it by changing the Here2 to number 1 priority - at least the calibration then completed much faster & with healthier values.
Does anybody have any thoughts? This was quite a scary encounter, because the copter throttled up & lifted off while I had the throttle stick firmly held to zero.