Hi,
We recently experienced a crash while doing a sortie. The vehicle suddenly flipped, stabilized and flipped immediately leading to a crash. We flew this setup for over a week and the vehicle was completely stable. This sudden crash put us into hinsight. Can anyone give insights on why it happened??? I am attaching both the stable as well as crash flight logs here in this drive link.
There are two log files in this attached google drive.
00000017.BIN - This is our crash flight log
2026-06-03 12-12-06.bin - This is the log from the previous day flight where we flew for more than 40 min without any issue.
While reviewing these plots, we found that the flight controller suddenly demanded an sudden roll and pitch command, when we investigated why the initial roll and pitch happened right after which the controller went into to chaos, if you notice in the above graph the vz ( which is pointing down NED so when climbing it should be negative) went from -2.5 m/s clib rate to 0m/s and then 1m/s (freefall condition for 2 second) while QTUN ThO is the throttle output demanded by controller for hover 0.29 is enough but it shot up to 100% throttle but the climb rate could not be achieved. So we suspect one of the motors might have failed but when we checked the esc and motors after the crash, there was no sign of any burnout in the esc. Then we were back to square one cause the craft which flew nearly stable for more than 40 min the other day crashed immediately the very next day. The only confusion is why this has happened?? Please look at the above plots to see if you can find something useful
Something is wrong with Motor 3 (SERVO8) and possibly motor 2 (SERVO7). You can see them commanded to full power but the current flow doesn’t rise to match. The FC is trying do it’s job by telling the motor to speed up, but for some reason it’s not happening.
No ESC data so can’t dig much deeper, but you’ll need to look at power to the motors/ESCs, physical connections. Also make sure the props are secure and not coming loose.
Okkay @Allister We will sure look into the esc connections once again.