Sudden crash from stable loiter

Request help with my APM 2.6.

I was flying in a stable loiter and the copter suddenly banked right. I switched to stabilize mode, gave throttle and opposite bank input, but had no control over the hexacopter and it slammed into the ground.

The same day I did a few flights in loiter and one in FPV whilst loitering. I had problems previously with my AV Tx which interfered with the GPS, but I repositioned the GPS and AVTx and put a thin aluminium plate between them and connected the plate to the ground of the drone.
All appeared to be working and the drone maintained position.

Log is attached.

The software is ArduCopter 3.1.5
Hardware is:
3DR APM 2.6
Chinese Ublox … 28633.html
Six Turnigy Plush ESC-s 25A
Six Turnigy NTM propdrives 2830s with 900 kV
Power system 4S

Thank you very much for your help in advance!

P.S - what I plan to do, is swap the GPS for a 3DR original, use a less powerful AV Tx and reposition it even further form the GPS. Also check all my ESC signal wires etc.

Are you using simple or super simple mode? I had similar issues and crashes; no control once it decided to do its thing. Your GPS hdop is consistently >2. Same here. Per MP, hdop >2 is not good, so if the flight mode relies on GPS, it appears to get confused or something and the stick control movements go ignored. I’ll be watching this thread.

I’ll add no FPV or other mods were done to my Y6B DIY. It is all 3DR.

Neither. I was in Loiter, and on recognition of problem swapped the threeway switch through alt-hold to stabilize.

Yes, hdop was poor, > 2 throughout the entire flight, but it looks like that didn’t have anything to do with the crash. The roll to the right was uncommanded, you probably had a hardware failure.



I just now had time to start rebuilding it and one of the motor wires was loose from the banana connector. The heatshrink still held it together.

Mechanical failure.

P.S - Cut away all the bananas and soldered wires Motor-ESC.