A friend recently reminded me about a problem we used to have back when I used to fly RC pylon with nitro powered planes.

The problem was you would accidentally bump the transmitter switch to the off position running back to your flying position after verifying the radio was on and starting the engine. To reduce the possibility of bumping the slider to the off position, we used to remove the plastic cover off of the slider switch.

One photo shows the switch cover as installed by the manufacturer. The picture on the right shows the cover removed. You can use a small blade screw driver to pry the cover u to remove it.