Arducopter Crashes While in Loiter

Hi Guys,
I have a large quad copter (About 800mm) running Arducopter 3.1.2.
The copter hasnt been fine tuned but for the first 10 or so flights, it was ok. On the last fight, i wanted to test the range of my antennas…telemetry, radio and video antennas. I managed to fly up to 1KM away in loiter mode. I had geo-fenced at 1km so the APM engaged RTL. On the way back, i wanted to take over and fly it again, so I switched to loiter. The copter then started drifting away then finally crashed hard from about 130 meters AGL.
Someone please analyse my logs and advice me on what could have happened. I checked the airframe for signs of any loose wires or connections but there was none. Seems like the copter somehow just disarmed while 130m AGL.

Hello Chris, I had a look and I can’t really make heads or tails over what happened. Are you sure you attached the correct log?

I don’t show any period of Loiter at the end. It’s an RTL from your switch point to the end of the log. And it almost looks like a totally normal RTL to touchdown, from what I can see? It looks like it move to a target, reaches it, holds position, then descends under control and lands.

Sorry, I’m trying to post more, and a couple graphs, but the forum is not working well for me at all so I can’t.

My initial reaction was the same as [quote=“Rob_Lefebvre”]Hello Chris, I had a look and I can’t really make heads or tails over what happened. Are you sure you attached the correct log?[/quote]

Altitude alone looks pretty non-crashlike.

thanks for replying. I attached the wrong log. im so sorry. Here is the correct one.

Clarification on the fence breach. At the beginning of the flight, geofence was at 300m. After the first fence breach, i increased the fence radius to 1000m.

I have reposted this on a new post here:

viewtopic.php?f=25&t=6546