What exactly is "stall"

[OTTOL]

Thanks for your input chortlsnorksnack, we'll call you when your shuttle arrives.....

[OTTOL]

And notice that while, at least, the pilots and instructors of "aircraft" have some certification, training, experience and knowledge requirements, those are not applicable to ultralights.

By FAR Part 103, a person does not need to meet ANY requirements of licencing, training, experience, knowledge, medical condition or age to fly an "ultralight".

By the same FAR Part 103, an ultralight does not need to be registered in any manner, nor bear any markings.

The airframe of an ultralight does not need to meet any certification requirements. Which implies that a person does not need to meet any requirements of knowledge or age to build an ultralight, or design an ultralight.

Verifying the empty weight is a simple matter of weighing. Verifying the fuel volume - ditto.

But how does one establish the exact stall speed? If you stall, and happily recover, at 25 knots, you should never have taken off to begin with...

Hokay...now that I'm home and in a little more positive frame of mind, I'll try to a little more constructive.

You might want to consider focusing a little more, simplifying your ideas and trying to stay on one subject. If you're serious about this subject (the stall question and not the other five subjects that you covered in the last post) , you may want to check this out...

http://www.grc.nasa.gov/WWW/K-12/airplane/incline.html

Although most airfoil diagrams you see are two dimensional, wing dynamics are, most certainly, three dimensional. Actual scale, spanwise flow and final production variations are just a few factors that make the determination of stall speed much more complex than just a simple equation. "How do most manufacturers determine Vso?", they fly the airplane and take notes.

[chornedsnorkack]

Hokay...now that I'm home and in a little more positive frame of mind, I'll try to a little more constructive.

You might want to consider focusing a little more, simplifying your ideas and trying to stay on one subject. If you're serious about this subject (the stall question and not the other five subjects that you covered in the last post) , you may want to check this out...

http://www.grc.nasa.gov/WWW/K-12/airplane/incline.html

Although most airfoil diagrams you see are two dimensional, wing dynamics are, most certainly, three dimensional. Actual scale, spanwise flow and final production variations are just a few factors that make the determination of stall speed much more complex than just a simple equation. "How do most manufacturers determine Vso?", they fly the airplane and take notes.

Sure. The wing dynamics are three-dimensional. But even in 2 dimensions, there is plenty of complexity.

After all, the pitch freedom of motion covers 360 degrees. As you see, the drawing on the NASA website breaks off shortly after stall. (around 15...20 degrees AoA) This tends to be a problem with most other websites as well - they break off the discussion at stall and do not describe in detail what happens on larger angles of attack.

Well, what does happen?

[OTTOL]

[quote]
Here, Ottol..