Increasing power required with altitude.. what's a good plain english explanation?

"RST Engineering" wrote in message
...
I'd suggest a REALLY GOOD flight review next time you need one with a
REALLY GOOD instructor who knows the relationship between power, altitude,
and true airspeed.

Or did ..maniac assume a pseudonym?

As you can probably see by the length of the thread, this one has gone on
for a while. I was talking about trying to explain the phenomenon of how to
keep the same IAS you need higher power as you increase altitude, but
without actually referring to concepts like IAS and TAS. I wasn't talking
about TAS increasing with altitude. I should have made that clearer in the
initial post. The whole thing started when a non-pilot friend of mine asked
how high planes could fly. I said that it depended on a few things, one of
them being the fact that engine power decreases with altitude because of air
density. At some point you'll hit an altitude where it can no longer
generate the power required for level flight. HOWEVER, even if you have an
engine that was turbocharged so well that it didn't lose power with altitude
all the way up to space, you'll still probably hit a limit (unless the
engine was extremely powerful) because the actual power required goes up
with altitude as well. Is there anything unreasonable in what I have just
said there? I don't think so. Where I went wrong is in not explaining my
question well enough, and people very reasonably thinking that I either
meant TAS or how open the throttle has to be.

As has been established, I am now certain that my understanding of power,
altitude and TAS was and remains correct. I was merely seeking a good layman
non-mathematical explanation of it. Hardly a major sin, I think.