> It would make some sense as mis-managing the fuel-air mixture on a small piston plane can lead to catastrophic failure. (frozen carb for ex) Carb freezing do

> It would make some sense as mis-managing the fuel-air mixture on a small piston plane can lead to catastrophic failure. (frozen carb for ex) Carb freezing doesn't occur as a result of mixture mismanagement, but rather by failure to apply carburetor heat when flying in conditions conducive to carb icing. Mismanaging the mixture is far less likely to have any acute effects. Descending with a lean[er] mixture may cause issues at lower altitudes where the mixture would be too lean, but it would be unusual for that to lead to an engine stoppage. Further - a pilot inexperienced in mixture management would likely not lean the mixture at all and just fly full-rich which again, wouldn't likely lead to any acute failures, just higher fuel consumption and longer-term issues with the engine.