I was flying around and i crashed my quad up side down into the dirt. When the crash happend I heard the motors making a twitching sound. Then suddenly a few seconds after the crash the quad was going full throttle in the dirt. I did not give any throttle nor do i have some kind of fail-safe in the  Devo10 transmitter or CC3D.
It was pretty dangerous and i actually cut myself trying to pull the plug. Next time iam bringing leather gloves in case it happens again so i can protect my fingers.

Do you guys have any idea what could have happend?

So in short:

• The quad was full of dirt (no mud, so not really wet dirt)
  

• I had the throttle set to 0% after the crash.
  
• I turned my transmitter off after the crash.
  
• The CC3D has its default fail-safe set to -1% which means it wont go to a x % throttle when it loses signal.
  
• The transmitter has no fail-safe values set to any channel.
  
• One of the antennas was cut in half.
  

I suppose the receiver just glitched out cause of the dirt. But maybe something else caused it. I hope you guys can share some experiences.

do you have airmode? my feeling tells me the failsafe didn't work... and like you said RX mul-functioned.

Never, ever turn off your transmitter while the copter is still powered.
Also, CF/BF have a 2 stage failsafe now. It's possible that you didn't set the second stage up properly.

I made a little movie about it:



I figured it was the throttle channel transmitter fail-safe not being set. I fixed it to go to 0% throttle if i turn the transmitter off.
I also relocated my xt-60 connector be in a better spot so i can just simply pull the plug if i need to.

Thanks for the replies.

make sure you bench test your failsafe.Nice job on the video

I did something like that once on landing and watched it run wide open upside down. I land goggled up in stabilized mode. The quad was trying to level it's self. I switched it to acro and it went to idle and was able to disarm.