Confusion about when it's my navigation, and when it's ATC

Mxsmanic wrote:
TxSrv writes:

For starters, the program doesn't really understand air
density. The program tries, but only in MSFS can one
maintain a semblance of controllability in a 172 at FL 250.

That would probably be a flaw in the specific model.

All planes, and various propulsion systems, react in the
same way to air density. The program itself could handle
this, needing only some specifics from the model file and
which it does supply for certain things. Whatever. Of the
zillion FS planes out there for download, point me toward a
normally-aspirated, piston aircraft, with certificated HP in
the model file, and which isn't a real hoot when slewed up
into the flight levels.

Plus, the mixture control does not react as it should at
even 7000.

What does it do wrong?

The red knobby thingy? Besides doing little but being an
on/off switch? I dunno. Regarding rarefied air, I read
somewhere on the net it's just the way carburetors work.

F--