Arduplane aggresive turns in RTL leads to crash

Hi Everyone,

I had a nasty crash where the plane disintegrated into bits… Very sad, but I guess it is an opportunity to learn something new!

I fly a ZOHD Nano Talon which was around 686g (too heavy I believe)

I take off with auto, take off waypoint to 30m, and another waypoint at 40ms. The mission is completed successfully, I fly FWBA for a while. Before the crash I switch to RTL to put on my FPV headset. the crash happens in RTL mode. The steep turn is done by the RTL which led to the crash.

I have a very good video of the event

The crash happens at the very end.

Here are the logs:
00000018.zip (2.5 KB)

I couldn’t analyze the log because it complains about missing FMT headers.

I have other flights where arduplane attempts to very risk turns whenever it is switched to RTL, or Loiter. My plane is destroyed so I won’t be able to replicate the issue again. I’m building a new plane with a different frame. I will try to replicate and get good logs if we can’t figure out what is wrong this with one.

My assumption:

I just played around in the simulator to see how it turns there. If you trigger rtl in a very closeby location It will do an incredibly aggressive turn ( 60degrees). I believe my plane stalled while trying to do this aggressive turn, because it was too heavy. As I watch the video I see that my plane tries to do a 90degree turn…

Is there any way to recover the log file?

Sorry for your crash,
agrressive turn not entirely what caused your NT plane to crash, NT from the start had problems with the control surface, I suspect the rudder did not return to the neutral position so the plane continued to turn

ardupilot can’t do anything about it because it’s out of control, if you want to make your NT fly “NORMAL” then this is what you should do

*btw: yes that was correct 686gr are too heavy

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I see. Thanks for the reply