Mxsmanic , IFR sensations, and some other stuff

On May 24, 2:59*am, wrote:
On May 23, 7:52 am, Bertie the Bunyip wrote:

wrote i
* * * So it's a process to cause the air to exert a force in a
direction perpendicular to the airflow. It fools the air, if you like,
which is why we call it an "air foil." A foil is a device to deceive.

Actually it's a synonym for blade.

Not quite. From the Merriam-Webster Dictionary:

* * Foil:
1 obsolete : trample
2 a: to prevent from attaining an end : defeat always able to foil
her enemies b: to bring to naught : thwart (foiled the plot)
synonyms: see frustrate.

* * * So my "deceive" is much less accurate than "frustrate."

* * * *Your definiton matches one of the the Cambridge Dictionary's
definitions:

If you look a bit further in the MW disctionary you will see both
blade and keaf. But the key is to use a proper dictionary like the
OED. Your definition of foil is a verb, not a noun and an aerofoil or
air foil is a noun.

Cheers

On May 22, 6:00 am, Mxsmanic wrote:

I'm only interested in flying.

You should try it sometime.


-c

wrote:
On May 22, 5:36 pm, Some Other Guy wrote:
BDS wrote:
There is an interesting article in Flying magazine by Peter Garrison that
talks about lift theory.
I thought that one of the most interesting points he made was that the
lift force generated by an airfoil is greater at the optimum angle of
attack than would be the force imparted to it if you were to move it
through the air perpendicular to the air flow at the same speed.
I first experienced this as a kid, sticking my hand out the car window with
the thumb as a leading edge, forming a crude airfoil.

When at the right shape and angle of attack, the lift is amazingly strong.
I always found it remarkable that when my hand was completely
perpendicular to the wind, the force didn't seem as strong.

Definitely a visceral lesson in lifting versus stalling.

I have a copy of that article here. Very, very good. The
coefficient of lift, as he described it, was a ratio related to the
lift generated by a unit area of wing compared to the flat-plate drag
created by the same unit area perpendicular to the airflow. The Wright
brothers did this in their wind tunnel, so they were able to develop
efficient airfoils. A common airfoil (NACA 23012, IIRC) has a max lift
coefficient of 1.8 , which means that it generates 1.8 times the lift
as the drag of the perpendicular surface of the same area.
He made things really clear when he pointed out that this is why
boats and ships no longer use paddlewheels. The wheel will produce
forward thrust equivalent to the power required to force the paddle
back through the water, while the propeller (they call it a "screw")
will produce much more forward thrust for the same torque required by
the paddlewheel.
So it's a process to cause the air to exert a force in a
direction perpendicular to the airflow. It fools the air, if you like,
which is why we call it an "air foil." A foil is a device to deceive.
Bernoulli is right, and so is Newton. There's a pressure
difference because of the difference in airspeeds between top and
bottom, and there's a movement of air downward to which there's an
upward reaction. The equal-transit time theory is bogus, since the
airfoil is much more efficient than that theory would imply. See this
page:
http://www.av8n.com/how/htm/airfoils.html
And, again, Mxmanic has declared, for about the 12th time, that
positive AOA is necessary for lift. If this was so, and it isn't, and
he has been shown many times that it isn't, then airfoils like the
Clark Y wouldn't generate lift at AOAs as low as -4 degrees. That's
negative 4 degrees, airfoil chord pointing downward. A graph can be
found a third of the way down this page: http://lpmpjogja.diknas.go.id/kc/a/air/airplane.htm
That page also deals properly with both Newton and Bernoulli.

Dan



Perhaps if we stray from a Clark Y and discuss symmetrical
airfoils............... :-))

--
Dudley Henriques

On May 22, 1:08 pm, Mxsmanic wrote:
writes:
What about rocket propulsion in a vacuum? How does that work?

Simple action and reaction.

Mmmm...but your action has nothing to react against, there's nothing
to push down on like you said with downwash producing lift for an
airplane wing.

On May 19, 2:27 pm, Bertie the Bunyip wrote:
Daedalus wrote :

On Mon, 19 May 2008 18:52:05 +0000 (UTC), Bertie the Bunyip
wrote:

Daedalus wrote in
m:

On Mon, 19 May 2008 17:10:55 +0000 (UTC), Bertie the Bunyip



wrote:

"Ken S. Tucker" wrote in
news:f41822f7-8b58-4810-bf30-97634fd4dec3
:

On May 18, 5:09 pm, Dudley Henriques wrote:
Ken S. Tucker wrote:
On May 18, 4:09 pm, Dudley Henriques
wrote:
Ken S. Tucker wrote:
On May 18, 3:34 pm, Dudley Henriques
wrote:
Capt. Geoffrey Thorpe wrote:
"Dudley Henriques" wrote in message
...
...
Without getting into a whole magilla concerning right and
wrong, simply let me say that in my opinion physical
sensation
should never, and I repeat it again so that there's NO
mistake....NEVER be used to verify or augment an
instrument
reading. In my opinion, this is what proper scan technique
is
all about. You verify instruments CONSTANTLY using other
instruments, right on down to primary panel if necessary,
but in my opinion, the basic concept of ignoring physical
cues
and sensations while on instruments is a sound principle
ans
should be followed to the letter.
...
I won't argue with a single word of that.
But...
That doesn't make physical sensations irrelevent or
unimportant. In fact, it is the MISLEADING sensations that
are
very important in the sense that, if you don't have
significant
experience "playing over" them, one typically ends up dead
(in
real life). Sitting on your lazy boy, those sensations
don't
happen - you always feel "coordinated" - you don't get
disoriented, you don't experience vertigo - which makes
flying
in simulated IMC stupid easy compared to real life.
And, I would argue that _no_ _ammount_ of desktop
simulation
will _ever_ prepare you for the assult on your senses that
can
happen when things aren't going well in real life soup.
One may think that one can handle real IMC based on desktop
experience - but without realizing just how difficult it is
to
ignore your inner ear screaming lies at you, one doesn't
really
have any idea what flying real IMC is like - I would bet
that
an experienced "sim only" pilot would pull the wings off
in
less than 3 minutes in real life.
I believe you and I are in complete agreement. Perhaps
something
being misread.
The understanding of sensations and how they interact with
the
IFR experience is of paramount importance. In fact, a lack
of
this understanding can get you killed quicker than anything
else
I can think of at the moment.
Where I was referring to the sensations issue was directly
concerned with one pilot who commented that verifying an
instrument reading with a physical sensation was important.
My
point was that instrument verification should be done
against
other instruments with the EXCLUSION of physical sensation
from
that equation.
When I was a kid, I was spun to dizzy, and
then staggered when I tried to walk. IIRC it
took a concentrated focus on some point to
sustain balance, which is me in VFR, but that
doesn't work in a fog.
Another thing I noticed is flying VFR with a lot
of turbulence, (especially with towering cumulus)
screwed my inner ear.
(That is my weakness).
I was very lucky that after just a couple of hours,
my flight instructor got me going on IFR.
He knew I had a basic handle on geometry and
algebra so he was the type to promote the advance
early on in instruction.
Ken
I tend to keep things on the basic level with students. It
helps
to hide my shortcomings :-)

After a few hours, my instructor had me doing shallow
(30's), medium (45's) and steep (60's) turns and would
critcize me because I focused on the VFR horizon and
he'd smirk and point to the Indescent Indicator showing
a 50'/per minute loss, and the IAS loss of energy and
my off-center-ball, so my turn performance was gauged
by instruments.
Obviously, I should have pulled a bit more elevator,
put on some RPM, and applied more rudder, so that's
what I did via instruments, and that's in a well done
bank at 60 degs even when VFR is available.
Ken

I'm the reverse ytpe of instructor. Initially I like students to
get
their heads outside the airplane and discover nose attitudes
(LF;Climb; glides) THEN after they have a good understanding of
these
nose attitudes I get them to cross check these attitudes with the
panel. Different strokes for different folks
Dudley Henriques

I was a Professional teacher for awhile, and so
understand the attitude.

Bwawhawhhahwhahwhahwhahhwhahwhahwha!

We did about 5 hours of night flying together,
he didn't say much by that time, except the odd
ancedote.

"oh ****, watch what you are doing!" is not an anectdote, fjukkwit.
Oh wait, maybe it;s a "ancedote"

Maybe it's an antidote!

Jade

Maybe it was an antecedant.

BTW, you wanna watch Larry, he has your number.

Bertie

Is that who keeps calling and breathing heavily?

THXS!

He mayb be crude, but he's cheaper than those 1-900 numbers.

Bertie

Speaking of cheap; you can replace the artificial horizon- how can you
tell when the wings are level?


Wait for it.



The CFI drools out of both sides of his mouth.

On Fri, 23 May 2008 12:59:08 -0700 (PDT), wrote:

On May 22, 1:08 pm, Mxsmanic wrote:
writes:
What about rocket propulsion in a vacuum? How does that work?

Simple action and reaction.

Mmmm...but your action has nothing to react against, there's nothing
to push down on like you said with downwash producing lift for an
airplane wing.

huh??? the push is against the inside top of the rocket.
the hole at the bottom where all manner of stuff rushes out is in
reality the part where the push is missing. ...thats for a gunpowder
rocket.

for a nasa fuel rocket the push is against the conical part of the
rocket motor because of the way the pressure is generated.

....its not rocket science you know!

Stealth Pilot

"Bertie the Bunyip" wrote in message
...

Good link but I think he kind of munged up the lift/drag thing as being
seperate entities, when they're inextricably linked. IOW you create lift
and drag is a by product. Not to say, BTW, that the correlation is
rigid!


Bertie

Posted by a forger.

"Bertie the Bunyip" wrote in message
...


Nope, I know it.



Bertie




Posted by a forger.

"Bertie the Bunyip" wrote in message
...

So I'd say arfoil was not used becasue of it's ability to frustrate air (
engineers just don't think like that, they seek harmony) but more because
of their resemblance to a leaf or blade.
Actually, the one in that link that stands out is the architectural one.


Bertie

Posted by a forger.

More_Flaps wrote in
:

On May 24, 2:59*am, wrote:
On May 23, 7:52 am, Bertie the Bunyip wrote:

wrote i
* * * So it's a process to cause the air to exert a force in a
direction perpendicular to the airflow. It fools the air, if you
like,

which is why we call it an "air foil." A foil is a device to
deceive.

Actually it's a synonym for blade.

Not quite. From the Merriam-Webster Dictionary:

* * Foil:
1 obsolete : trample
2 a: to prevent from attaining an end : defeat always able to foil
her enemies b: to bring to naught : thwart (foiled the plot)
synonyms: see frustrate.

* * * So my "deceive" is much less accurate than "frustrate."

* * * *Your definiton matches one of the the Cambridge Dictionary'
s
definitions:

If you look a bit further in the MW disctionary you will see both
blade and keaf. But the key is to use a proper dictionary like the
OED. Your definition of foil is a verb, not a noun and an aerofoil or
air foil is a noun.

Cheers

Yeah, but the verb as it;s used has also become a noun. But I do believe
that the noun as it applies to a blade is probably the origin of it
being applied to wings and fins and other bits.




Bertie