"Marty Shapiro" wrote in message
...
Have you ever driven a non-turbocharged car from a low lying city up into
the mountains, like above 5,000' MSL? If you did, you would understand
why
the pilot has to manipulate the mixture.

Unfortunately (for the purpose of your example anyway, which is otherwise an
excellent one) most if not all modern cars use an air mass meter to ensure
correct fuel metering. High altitude driving doesn't require a carb
readjustment any more...the car's engine just compensates. Less power is
the only noticeable symptom, and I doubt most drivers are with-it enough to
notice that.

Also, the design of the aircraft engine is such that once it is started,
the engine driven magnetos provide the spark to keep it running. You can
have total electrical failure and the engine will keep on running. How do
you stop the engine after you land?

Well, you could use the fuel cut-off valve, or you could short out the
p-leads to the magnetos, as alternatives to setting the mixture to the fuel
cut-off setting.

IMHO, the main reasons that aircraft engines require so much fiddling is
two-fold: one is that aircraft engines operate at constant settings for most
of the time they are on; another is that improvements cost big bucks in the
form of certification costs, bucks that most pilots won't pay when the
current (albeit ancient) technology suffices.

Pete