Air temperature changes with air pressure changes inside
engines and also around the wing and tail surfaces. Also,
temperature probes are not 100% accurate, so the +5°CF is to
provide a cushion.

Exactly what is turned ON depends on the airplane and the
type of ice protection installed.

It is important, something as simple as a temperature probe
also needs to be anti-iced to prevent any ice accumulation.
Other systems do de-icing, allowing some ice build-up and
then removing that.

King Air using P&W PT6 engines have ice deflector vanes that
deflect water and ice particles from the air going into the
engine. The intake lip on older King Airs had an electric
heating element, newer designs are heated by engine exhaust
being routed through a hot lip which gets hot any time the
engine is running.

Jet engines produce a lot of hot air by compression inside
the engine before the combustion section. Some of that hot
air is bled away and used to heat the air inlet to the
engine, electricity may be used to heat temperature probes
in the inlet. Smaller engines don't have as much hot bleed
air available, so they may use bleed air only for the air
intake and cabin pressure/environmental while a big airliner
probably uses bleed air for engines, wings, tail and other
areas. Some airplanes with multi-disc brakes may use a hot
air distribution manifold to send hot air to the brake
assembly so that the brakes are not frozen, this is turned
on a few minutes before landing and during taxiing in water
and slush/snow and is usually on a timer so it turns off
automatically about 10 minutes after gear retraction [the
switch then needs to be manual turned off to reset the
system for landing].

Pitot and windshield heat, are OK to run all the time in
flight, but if pitot heat is used on the ground for a long
period, the chrome will turn a pretty purple, so test it on
the ground [don't burn your hand] and then turn it on before
take-off.

Too many systems to explain here, read the POH or a good
training manual.




"Gary" wrote in message
oups.com...

Mxsmanic wrote:
From what I understand, icing protection should be turned
on if the
outside temperature is 5° C or less.

Also, what types of anti-icing stuff should I turn on?

Just turn up the heat in the room where you run your
simulator, and
you'll be fine.