OK, I have about 50 hours flying this particular multicopter. I was documenting some levy's for some farmers when I lost control of the Hexa. You can see from the DVR that I lost control when I went from Stab to Loiter then Stab. This switch from Loiter to Stab was the moment it went into a violent flat spin and crashed.

Any ideas what happened?


(Apm 2.5)

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Any chance of logs?

Knew someone would ask that. No, I was having problems with my lap top.

I am having this same issue, except with a quadcopter. I am using an APM 2.5 with the Mediatek GPS. I haven't done too much flying with the current configuration yet, but during the last testing run we were testing waypoints. Stabilize mode is definitely working very well.

The first time it happened was when we were tuning loiter. The copter was circling a little bit, so we switched it back to Stabilize and it practically flipped out of the air.

The second time it happened was when we were testing waypoints. When we flipped the switch for Auto, the copter starting going off quite a bit to the left of the first waypoint. However, when we switched back to stabilize the copter starting spinning and flipping before crashing to the ground (we did cut throttle shortly after loss of control).


It seems that it may have something to do with the GPS not working quite right, and then switching to stablize. I don't want to jump to conclusions though.

The log files are of the second time it happened. It's roughly one hour of flight testing, and the crash is at the very end. We had just switched to a new battery, which was also fine afterwards, so that's not the problem.


Anyone know what's going on?


How about a log from the APM board itself (not the tlog)?

Stupid Question Alert! How can I pull down the APM logs?

In Mission Planner, go to the Terminal tab, and connect to the APM. Then click "Log Download." Choose the logs you want to download, and click "Download These Log." Those log files will be downloaded to where Mission Planner is installed, for example: Program Files>APM Planner>logs>logname.log.

Smth like that happend to me on 2.9.1.

Suddenly lost control. Copter was swinging like in your video totally out of control.

Hi Franton,

Did manage to get the APM Planner logs into a file with a ".log" extension. I clicked on the file but nothing is happening. Any ideas what I should do next? (I am a Mac guy using a Windows laptop for access to the MP.)

You have to open the log with the 'Browse Logs' button, then you can plot a variety of data as a graph.

It's all in the Wiki: http://copter.ardupilot.com/wiki/common-downloading-and-analyzing-d...

Thanks Graham.

Will look at the Wiki and see if I can figure it out. I am including a log file that I believe is the data I should be looking at. The crash happened on log 94 and that is the log I am focusing on.



I have been looking at the data logs for this flight. As I try to understand what I am looking at, it is clear that what ever happened, happened very quick and profoundly. When I plotted the altitude chart, the final plunge was dramatic. There was either a mechanical malfunction, a data error, or pilot error. Which ever it was, I  (and apparently many others)  would like to know.

I am attaching the data log so that hopefully someone can detect what ever it was that caused the crash. I would be more than happy to do it myself if I knew how and yes I read the wiki that was suggested. (BTW, take a look at where the geo coords are of the crash site. I was VERY Lucky to have found it. The launch site was over a half mile away it HEAVY vegetation.)

Thanks for any help on this one.



I have the same problem many time, I can't find the reason, attachment is last fly log and tlog, anyone can analysis it and find out the reason.

Thank in advance


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