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

What's false about the assumptions? He's talking about flight at the same
angle of attack at different altitudes.

Are you serous?
First, take a look at his opening statement.We dont fly planes like
this in real life.It seems he has made the deductions first, and then
came up with the opening statement.Also, not all of these deductions
can be true at the same time.

The purpose of that section is not an operational guide. It's merely to
illustrate a point -- that being the effect of flying at the same angle of
attack at different altitudes. This leads to the last point: to do that you
need more power.

I don't see which one of the deductions isn't true given the parameters.

The TAS will increase, but say you want to hold a specific angle of
attack
and its attendant IAS (maybe for range), you will need more power to do
that
as you get higher.

That is correct, but that was not your original question.

Well, it's related to the original question, I think it's fair to say.

On Feb 3, 12:15 pm, "Andrew Sarangan" wrote:
On Feb 3, 10:36 am, "alice" wrote:

John Denker is a highly respected author and his book provides some of
the clearest explanation of the aerodynamics without resorting to
complex mathematics.

Andrew, This is open to debate.I went and read some of this "Book".It
proves the old adage dont believe everything you read on the web.You
need to understand that Denker is just expressing his opinions, and
this could be why he doesnt use any math to back it up.That being
said, I can respect Denkers opinions but they are just that.I would
like to know where some of his assumptions come from.

This particular section is not about how
airplanes are flown in every day life, but an indepth exploration of
the factors that influence power, density, drag and AOA.

I can appreciate the fact that Denker is using a classroom situation
to prove a point, but in order for his explination to be true, you
have to suspend certain realities about how a plane flies.Tell me how
this helpfull.

Just because
you operate a jet does not make you an expert in aerodynamics.

Ouch, dude I never claimed to be an expert did I?Now I will claim to
know what I need to know to fly an airplane, and I have seen Denkers
type before.He thinks you have to go deep into therory in order to be
a safe pilot, and ironically, he doesnt always get the therory
right.Mabe there is a happy medium somewhere between being able to
design a plane, and just going out and flying it.

If you are able to provide a better explanation, please do so, but it
seems to me that it is you who needs to spend some time reading up on
the basics.

Better explination for what?Why do you asume that I do not have a
grasp of the basics?Are you another troll.
KM

"alice" wrote in message
oups.com...
On Feb 3, 11:13 am, Mxsmanic wrote:
alice writes:


The real reason they fly high is for fuel economy.

OK MX, You are just toying with me.And, you got the last laugh.I am
kinda curious who you fly for and what they taught you in regards to
long range cruise.The only way your statements would work out might be
in a lightly loaded biz jet or something.Clue us in here.
KM

Here's your first clue (and it's the only one you'll really need...):

- He only flys for Microsoft Airways...

That ought to clear up a few things, eh?

BTW, welcome to the group. Feel free to post early and often.

Jay Beckman
PP-ASEL
Chandler, AZ

Better explination for what?Why do you asume that I do not have a
grasp of the basics?Are you another troll.


Explanation for why power requirement increases with altitude for the
same AOA. You said "this author comes up with the right
answer, but he uses some false asumptions.Its obvious he hasnt spent
much time in a real airplane". The latter part I find rather insulting
of the author, but I will leave it at that. At least you can explain
what the false assumptions are and what is your correct explanation
is. You can't just claim that something is wrong without providing an
explanation. That's what a troll is.

Mxsmanic,

Good physicists can explain any principle of physics without resorting
to math.


Jeeze, and now you're a physicist, too? This is such obvious BS.

But go ahead, explain quantum physics to us without math. You coud
actually make A LOT of money writing a book about it that way.

--
Thomas Borchert (EDDH)

Thomas Borchert writes:

But go ahead, explain quantum physics to us without math.

I'm fairly good at vulgarizations, but others are better. Try reading
Richard Feynman's lectures, or Issac Asimov's many vulgarizations of
complex topics that include physics. Einstein could also explain
things well if needed. Hawking does well in some of his work for the
general public. Many run-of-the-mill physicists are lost when asked to
explain things, however--presumably they lack the intelligence to do
so.

The reality is that people who actually understand physics can explain
it without resorting to math. The ones who use math are those who
have learned only the math, and have no intuitive grasp of the
subject. They are all too common these days.

You could actually make A LOT of money writing a book about it that way.

Some people have made a fair amount of money, although physics for the
masses isn't a hot topic. I'm not really interested in writing a book
at this time, although I've had stuff published in magazines. I have
some essays available for free download on my site on various topics
(not physics, currently, though).

--
Transpose mxsmanic and gmail to reach me by e-mail.

Mxsmanic,

your delusional qualities never cease to amaze me.

Oh, and in case you're wondering, yes, I do have a masters degree in physics, so I know what I'm
talking about. You don't. As usual.

--
Thomas Borchert (EDDH)

"xerj" wrote in message
...
I was trying to explain to a non-pilot why increased power is required with
altitude. She said "isn't the air thinner up there so there isn't as much
resistance?" I said "yes, but the plane needs to fly fast enough for the
air over the wings to feel like it does down low. So the speed required
goes up you get higher. More speed need more power."

This didn't really do the trick.

Can someone think of a better way of putting it without resorting to
mathematics and an explanation of IAS and TAS?

TIA


To fly the same IAS requires the same power. To fly the same TAS, requires
less power. Because the air is thinner, you need a higher throttle setting
to get the same power out of the engine. Maybe you are getting throttle
setting confused with power.

Danny Deger

Thomas Borchert writes:

Oh, and in case you're wondering, yes, I do have a masters
degree in physics, so I know what I'm talking about.

I don't recall saying anything about you.

--
Transpose mxsmanic and gmail to reach me by e-mail.