Fell/landed to a tree caused by unknown reason

Hi, Firstly I am really sorry about my english.
Today when I test my quad, it out of my sight. Then I look at to my phone which is connected to fpv vrx. It is out of range too. Then I look at mission planner on my pc(connected to quad via SiK telemetry system) after 5 secs it lost connection too. So I switched my rc transmitter switch for rtl(Works too good, tested for 10 times and every apm reset). But nothing on sky… I ran to the last positon on mission planner. Oh thanks to god my drone is there. Just flipped cause of trees, but there is no damage. So I think it landed. But why? I looked at the log. But there isnt a error. Why it is landed and not returned to launch? And in log seems
Thanks in advance…


Ublox m8n gps
Apm 2.6 in arducopter 3.2.1

Unfortunately your log file has very few parameters logged.
RCout would have been handy as it tells a lot about what the motors are doing.
Looking at the desired to actual values shows no real divergence or errors.

What I did notice was in the GPS you had a loss of some sats down to 11 which of itself is fine, your minimum is 6, but the HDOP jumped to greater than 1.4, which is the maximum for GPS flight.
At this point I am guessing it went into land mode as the altitude decreases and you have a ‘Land Complete’ message, which would indicate the Land command was followed.
The only problem with this is you were in Stabilise mode which should not have been impacted by a GPS problem.

I can’t see much else in the log

Thank you for your answer. Until it’s out of my sight, flight mode is always stabilize. (Cause of altitude hold and loiter not workinganother problem) So seems like this problem stay awkward because of too few log. Already I think it landed, because when I found it’s upside down but there isn’t any damage. I think most important part is why it landed. I didn’t do anything about landing. And in log there isn’t a fail-safe (At least I didn’t see). Lastly, why altitude is-20~ meters? Whatever thank you again. And anyone else who is try to help, thanks in advance…