Yep.  Had one fly away on me.   It was a Falcon 56 that I had flown for the first time just a few weeks before.  Must have been the summer of 1986 sicen it was well before I could drive.   I was relatively new to RC but had been signed off by the local club.  Went  to the local high school (Homestead - SW of FT Wayne, IN) and flew off the soccar fields.  Started it, ran through the final checks, took off and flew for about 2 min before it was heading off on it's own.   My father and I hopped into the car and took off after it.   We found it in a freshly plowed farm field several miles down the road.  It was upside down but not a scratch!  

Battery testers were very expensive and very rare back then.   I think we just bought a new pack the next week.  This plane is in my basement waiting for the snow to melt so that i can fly it again.   It's my go-to plane for spring to get the cob webs worked ouf of my fingers (i'm always lucky with this plane).   After this incident I used to turn on the planes and time how long they ran off the battery before quitting.  Now I just use my battery cycler but it was a valuable lesson that has saved several airplanes for me over the years.