AUTO mode did not resume well after CH5 mode glitch

Hi Guys,

I would like to ask for your help to understand what caused my unfortunate (but mild) crash.

I was flying in auto mode. when the copter suddenly decended from 100m survey height till it hit the trees. My buddies and I were having a good laugh so we werent able to monitor our laptop.

From the logs, I see that there have been glitches in the FrSky L9R receiver (with Channel 3- THR and Channel 5, which caused it to switch to Stabilize for half a second, then back to Auto). I use Horus X12S.

Granting that there was a glitch in flight mode, what baffles me is that the copter did not resume the mission. I have ticked the “resume mission” in the parameters. What happened was it did probably proceeded with the way point, but with a different altitude (i.e. 0 meters), causing the crash.

Here is the copy of the logs:
https://drive.google.com/file/d/1ac-3ve1AdzaCyfNslOFhdeKHrJn3xZz9/view?usp=sharing

Thanks so much!
Patrick

Looks like your primary (GPS1) went a little crazy just before it started to descend, causing a switch of primary GPS at 1310 seconds into log. Not sure if this caused the crash but looks strange, number of satellites drops to zero.
There also seems to be a large difference between desired roll and roll throughout the flight. Also seen in difference in roll between EKF (NKF1/6).

Cheers

Matt

Thanks for looking at my logs matt!

I noticed too the primary gps error. Its a here+ setup.

What I still dont get is why it decended. I noticed that after decending to about 2 meters desired alt, it triggered increase in altitude again, but crashed.

Thanks for noticing the EKF glitch, and this leads me to think that there was an EKF failsafe (as my FS is set to LAND even in stabilize mode). But there were no EKF FS errors noted, so im confused.

Cheers