Thrust line: a no-thought experiment.

In article ,
"Morgans" wrote:

"Alan Baker" wrote

I can't help noticing you've somehow missed the cutsie reply when I
provided an actual reference that shows that your entire notion is
bull****...

You have failed to understand the question. A paper that answers a
different question is no good for answering the original question.

No, it deals with the facts of the situation that show that your answer
cannot possibly the correct one.

In trimmed flight, aerodynamic drag and thrust *cannot* possibly be
pointed at one another except potentially at one particular angle of
attack.


I'm done this time. Really.

Go ahead and get the last word. I know you will.

Yup. You're running away having shown no math, no references...

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg

Alan Baker wrote:

In article ,
"Morgans" wrote:


"Alan Baker" wrote


I can't help noticing you've somehow missed the cutsie reply when I
provided an actual reference that shows that your entire notion is
bull****...

You have failed to understand the question. A paper that answers a
different question is no good for answering the original question.


No, it deals with the facts of the situation that show that your answer
cannot possibly the correct one.

In trimmed flight, aerodynamic drag and thrust *cannot* possibly be
pointed at one another except potentially at one particular angle of
attack.


I'm done this time. Really.

Go ahead and get the last word. I know you will.


Yup. You're running away having shown no math, no references...



But he was right, and you were mostly wrong.



--

Richard

(remove the X to email)

In article ,
cavelamb himself wrote:

Alan Baker wrote:

In article ,
"Morgans" wrote:


"Alan Baker" wrote


I can't help noticing you've somehow missed the cutsie reply when I
provided an actual reference that shows that your entire notion is
bull****...

You have failed to understand the question. A paper that answers a
different question is no good for answering the original question.


No, it deals with the facts of the situation that show that your answer
cannot possibly the correct one.

In trimmed flight, aerodynamic drag and thrust *cannot* possibly be
pointed at one another except potentially at one particular angle of
attack.


I'm done this time. Really.

Go ahead and get the last word. I know you will.


Yup. You're running away having shown no math, no references...



But he was right, and you were mostly wrong.

No. He was completely wrong and I was completely correct.

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg

"Alan Baker" wrote in message
...
In article ,
cavelamb himself wrote:

Alan Baker wrote:

In article ,
"Morgans" wrote:


"Alan Baker" wrote


I can't help noticing you've somehow missed the cutsie reply when I
provided an actual reference that shows that your entire notion is
bull****...

You have failed to understand the question. A paper that answers a
different question is no good for answering the original question.


No, it deals with the facts of the situation that show that your answer
cannot possibly the correct one.

In trimmed flight, aerodynamic drag and thrust *cannot* possibly be
pointed at one another except potentially at one particular angle of
attack.


I'm done this time. Really.

Go ahead and get the last word. I know you will.


Yup. You're running away having shown no math, no references...



But he was right, and you were mostly wrong.

No. He was completely wrong and I was completely correct.

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg

No, you are wrong!

The OP, Clare, was concerned about the effect of a deviation from the plans
for the aircraft he is building, and sought advice on this forum.

You, in turn, have fixated on a particular geometric relationship as though
it is always critical-which it is not. It is certainly interesting, and it
has been used to advantage in a few designs--such as the Ercoupe. The
easiest way to verify this is simply to watch an Ercoupe taxi past--it looks
"weird" because so few designs have their engine geometry adjusted to
trivialize the effects of propeller thrust.

However, in most single engine land airplanes, the effect is modest and
easily managed--although a slight nose up tendency with power is admittedly
the norm.

In the case of the Pegazair, which was the subject of the original question,
I can not even begin to guess whether a slight increase in the height of the
thrust line would cause a slight nose up or down tendency as compared to the
original design. My experience with Cessna 150s and 172s suggests that the
camber of the wing exerts a large influence on the horizontal
stabilizer--and I can not guess whether that effect would be increased or
decreased.

Peter