I must admit that when Brett first introduced his rules change to include a mechanical interlock to the battery circuit I thought it was a solution to a problem that didn't exist.  I was wrong! 

This past Saturday I was using my take-apart Ringmaster at the EAA show in Compton California when a very strange event occurred.  I let John Write fly the Ringmaster and everything from start to finish went perfectly.  The plane was sitting on the ground when helper not familiar with electric power systems and the correct way to "Safe" them.  Instead of following my procedure of  grip  the plane, switch off the timer, disconnect the battery, and then, and only then, return plane to pits.   I should have mentioned this in the pilots meeting for the benefit of people who are not familiar with electric power systems. 

The helper reached down to pick up the plane and that's when thing went terribly wrong.  When his hand touched one of the nuts securing the landing gear the motor powered up to max RPM the plane tried to take off.  Fortunately the last line of defense was in place, John still had the handle in hand with a firm grip.  The lines were slack which allowed the plane roll into a dirt area where some damage was done to the outboard wing tip and the prop mount on the motor.  Minor damage easily repaired.  This all happened in front of a crowd of people who were unfamiliar with model airplanes.

My opinion on what caused the problem goes as follows:  The day was warm and dry with a 5-10 MPH breeze.  The helper who picked up the plane was wearing tennis shoes.  I think he built up a fairly substantial static charge and when he touched the plane the static discharged.  Because the switch was still on the code in the microprocessor jumped to an area that brought up the motor, or the microprocessor in the ESC jumped into code that turned on the motor.  Somebody else may have a better explanation, but that's the best I could come up with.  I talked it over with Keith and he couldn't come up with a better explanation.  What I don't know and will never know was which microprocessor turned the motor on.  The one in the timer/governor or the one in the ESC.  Either could have done it.  The scary part is this plane did have the safety interlock, but before the battery could be disconnect the motor started up.    The very first thing that must be done when retrieving an electric plane is to get a good grip on the plane, then switch off, then disconnect the battery, and until the battery is disconnected from the ESC the pilot mush have a firm grip on the handle.

In the 2+ years that I have been using electric power I have never seen anything like this before, and I hope I never see it again.  "NO BS" guys this did happen.
Andy

Most likely it was the model that had the build-up of static, just as your car zaps you in the winter on a dry day. (Insulated by the tires)

Maybe we should install a spring-loaded metal skid next the tail gear