I believe Tony Bingelis would say to make sure the two control knobs are different. Different color is obvious, but also different sizes, and perhaps different types of lock to prevent accidental activation of the throttle when you intended to lean the mixture, for example.
I happen to have had this experience, on one of my first flights. Both throttle and mixture were the same size knobs, although one was red and the other black. I was climbing through crosswind and beginning to turn downwind and pulled the throttle back to end the climb and reach a lower downwind RPM. But I wasn't looking at the knobs...just operating by location, (without thinking) and pulled the "throttle" back quickly. It was actually the mixture knob, and the engine promptly quit. Not a good thing while in the pattern! It took a few seconds to determine what happened and it restarted instantly, but it could have been a lot worse! For that reason, I changed out the mixture to a much smaller vernier knob with a completely different shape. I never did that again, and set up N891JF in a similar manner. Mark Langford, Harvest, AL ML at N56ML.com www.N56ML.com
