THE AVIATORS Soaring Episode

Some may not know that Manfred does a show at Sun N Fun.

http://radiusairshows.com/index.htm

Gravity does not power our gliders. The forward tilt of lift is what moves us forward. The sun powers our gliders. ( after the initial boost from dead dinosaurs)

Gravity does not power our gliders. The forward tilt of lift is what moves
us forward. The sun powers our gliders. ( after the initial boost from dead
dinosaurs)


What came first, the chicken or the egg? I'm with you on the sun being the
power, but I gotta ask - what provides the forward tilt of lift?

Bob - I'll rack out now - W.

On 2/8/2014 10:13 PM, Bob Whelan wrote:
Gravity does not power our gliders. The forward tilt of lift is what moves
us forward. The sun powers our gliders. ( after the initial boost from dead
dinosaurs)


What came first, the chicken or the egg? I'm with you on the sun being the
power, but I gotta ask - what provides the forward tilt of lift?

Bob - I'll rack out now - W.

Sheesh...I really SHOULD rack out. I'll admit Mr. Sun is crucially important
to us actually soaring (i.e. gaining energy), nonetheless I'm pretty sure the
glider would still move forward in the absence of sunlight...but the FAA
frowns on my testing that hypothesis.

Bob - gravity never quits - W.

In article writes:
On 2/8/2014 10:13 PM, Bob Whelan wrote:
Gravity does not power our gliders. The forward tilt of lift is what moves
us forward. The sun powers our gliders. ( after the initial boost from dead
dinosaurs)


What came first, the chicken or the egg? I'm with you on the sun being the
power, but I gotta ask - what provides the forward tilt of lift?

Bob - I'll rack out now - W.

Sheesh...I really SHOULD rack out. I'll admit Mr. Sun is crucially important
to us actually soaring (i.e. gaining energy), nonetheless I'm pretty sure the
glider would still move forward in the absence of sunlight...but the FAA
frowns on my testing that hypothesis.

Bob - gravity never quits - W.


The glider would move without sunlight, but (short of the energy applied
during tow), the energy for climbing comes from sunlight.

Gravity provides a force to hold the air here, and a force to act through
distance (altitude) to provide us with foot-pounds of energy.

The forward tilt of lift is a result of the aircraft pitch angle.

Alan

Waveguru wrote:
Gravity does not power our gliders. The forward tilt of lift is what moves us forward.

Say what now?!?

You're flying in equilibrium, in unaccelerated straight line flight at a
speed just above the stall. You have a nose high attitude and a line
perpendicular to your wing surface is pointing rearwards. Where is the
"forward tilt of lift"? You'd need a lift distribution shaped like a
flaccid.....err, a slinky that's toppled forward to sustain this
hypothesis.

Your 'forward pointing force', the one that's opposing drag and "replacing
thrust" if you're of the powered persuasion, is the forward component of
weight. So yes, gravity is indeed our "engine".

CJ
B3

A rock has air and gravity when you drop it, but does not move forward through the air. Our wings provide our thrust to move us horizontally.

Boggs

Waveguru wrote:
A rock has air and gravity when you drop it, but does not move forward
through the air. Our wings provide our thrust to move us horizontally.

Boggs

A rock doesn't fall in equilibrium (until terminal velocity at least) and
it's forces operate in only one plane - the vertical. Can we compare apples
with apples please?

If you have sound reasoning to offer and preferably, a vector diagram, I'm
all ears.

CJ
B3

Sorry, CJ, but when pitched nose up with the lift vector aft, you can't maintain a constant speed (without an engine) since the horizontal component of your lift vector is directed aft hence the glider slows down. That is accelerated flight, though a negative acceleration (rate of change of velocity with respect to time = acceleration). Keep this up and you will stall.

The 'forward point force' in your example is rearward and amounts to drag rather than thrust. The weight vector is always towards the center of the earth.

"CJ" wrote in message ...
Waveguru wrote:
A rock has air and gravity when you drop it, but does not move forward
through the air. Our wings provide our thrust to move us horizontally.

Boggs

A rock doesn't fall in equilibrium (until terminal velocity at least) and
it's forces operate in only one plane - the vertical. Can we compare apples
with apples please?

If you have sound reasoning to offer and preferably, a vector diagram, I'm
all ears.

CJ
B3

Thanks for pointing out the flaw in my example Dan! You're right in that
the example I gave stated lift acting rearwards which in sustained flight
is incorrect. Whilst the aerodynamic force acts rearwards, the resolved
component of lift does indeed angle slightly forward, effectively, at the
glide angle. Where we seem to disagree (after agreeing that weight always
acts towards the centre of the earth) is that weight can be resolved into
two components. The component that opposes lift and the 'forwards
component' that opposes drag.

Figure 2-15 at http://avstop.com/ac/power_parachute/chapter2_7.html refers.
Where "WD" is the "forward component of weight" that I'm speaking of.
Not being able to draw here, I'm stuck using the works others - sorry!


CJ
B3

**reader not quoting properly; text below for context**
Sorry, CJ, but when pitched nose up with the lift vector aft, you can't
maintain a constant speed (without an engine) since the horizontal
component of your lift vector is directed aft hence the glider slows down.
That is accelerated flight, though a negative acceleration (rate of change
of velocity with respect to time = acceleration). Keep this up and you will
stall.
The 'forward point force' in your example is rearward and amounts to drag
rather than thrust. The weight vector is always towards the center of the
earth.

"CJ" wrote in message
...

Waveguru wrote:
A rock has air and gravity when you drop it, but does not move forward
through the air. Our wings provide our thrust to move us horizontally.
Boggs

A rock doesn't fall in equilibrium (until terminal velocity at least) and
it's forces operate in only one plane - the vertical. Can we compare apples
with apples please?

If you have sound reasoning to offer and preferably, a vector diagram, I'm
all ears.

CJ
B3