Gertrude
What do you do with the small amount of AVGAS that you sample from the fuel drains?
I got caught a few years ago, in an Archer, was running through some of the internal checks, after engine start, when the hairs on the back of my neck stood up.
Looking up quickly, I discovered that we were sliding down the icy taxiway at about 3kts, even though the parking brake was firmly on.
Power checks were fun - up and down the taxiway