1km mission, but didn't make 500m


The mission was to go 500 away and return. It failed just before returning.
No apparent errors before it started to act weird, only ERROR GPS-2 afterwards.
Check the logs.
My theory is that one ESC turned off, but maybe you can spot it better.

setup: quad
3S 5000mAh (battery voltage vas 3.9V per cell, so that looks ok)
11x4.7 nylon props
850kv iPower motors
Qbrain 4in1 ESC
Pixhawk 3.2.1

no wind, sunny.

clock here to access the log
dropbox.com/s/jaz2gj2vz3s00 … 5.log?dl=0

it wont let me attach it (>2mb)

Hi, i see your log.
for what i can say (i’m not the best-or medium- log analyzer here)
At 500 meters you had a GPS glitch problem. e the copter start to descent and ThrOut (autopilot thrust to the motor) increase and increase but cannot compensate and altitute keep to goes down.

Attitude values show that copter seems to follow desired values…execpt for the yaw during the gps glitch event and the starting of the descent.

Gps Glitch, maybe it was low, it applied the max thrust (battery read 10.5volts) and maybe it hit the ground due to the lack of power.

If the battery was 3.9v x cell when you recover it, and the autopilot read 10.5 under stress, maybe the battery it is old? i dont get a >+1 volt under load (at the middle or the upper end of the capacity, maybe at the end of the flight)