A week ago my tiger 2 was running badly, it has a super tigre 61 on it and it just for some reason wanted to be at idle or WOT. So i take it out to the back deck and place an end table that sets under the roof between some patio chairs, over the wings to restrain it. This table is at least a 10 pound table it is solid oak. I set my flight box on top of the table, so all together you are looking at 25 pounds or more of weight restraining the plane. I figured out the running issue, bad o-ring under the carb, changed it and ran it out a bit. I went to WOT leaned it a bit and the plane the table complete with field box on top moved about 6 inches across the floor...fast... Now it is a well kept deck so it was smooth, and the table had the little round plastic skids on the bottom of the legs.It was in no way as difficult as I thought it would be to move. That being said if someone had been close in front of it they would have got nailed by a 12x7 MAS at 10000+ rpm

I told on myself for one reason, PLEASE be absolutely sure that while starting a plane.The thing is completely restrained , the throttle is not wide open, your hands, your clothes, and any wires are all far far away from the prop. I have seen what a hand held grinder does when it catches a shirt, it is terrible, instant set of dentures required. These planes would be far worse.