I agree that the density of the air is a constant (at a given altitude and barometric pressure) so I see where that doesn't change. I also see why you don't agree because I mis-stated what I meant. I was referring to the "ratio" between the density of air, and the size of the object. It only makes sense that, that "relationship" would vary.
I agree that an f-104 and a vintage glider both use wings to maintain flight. However, there is a big difference in how they use them
There is no variable in that equation for thrust, it is not thrust that generates the lift.
Like I said I am not a mathematician (can't even spell :-) but if thrust didn't play a major part in lift, then why does an f-104 have such a different airfoil and wing shape as the glider? While they both must move through the air, in order to create lift (or the air must be moved around the wing), the F-104 MUST move through air much more quickly than a glider in order to remain flying. Since a glider has no engine, and an F-104 has a very powerful one, thrust MUST be a factor.
but that doesn't alter the fact that when flying in level flight regardless of speed, or weight, or thrust, a plane uses its wing to fly and not engine thrust.
Of course most airplanes use its wing to fly. The point I am trying to make is that they use wings much differently because of the thrust. Lift must be created by the wing to begin and maintain flight in most jet aircraft. An F-15 needs a wing (airfoil shape) to take off. But due to its thrust to weight ratio, after take-off, it is able to fly straight up and uses it's wing more for guidance and stability than for lift. As we have seen in the X-plane projects, airfoil shaped wings are not "required" to maintain straight and level flight. While it is true that most airplanes need airfoils to get airborn, once they are in the air, and if they have enough thrust, the airfoil is more of a hindrance than benefit above mach 1. And then, there are the flight characteristics of missiles. Thrust may not generate lift, but it sure has a big impact on flight.
I apologize for using incorrect terms and misleading from what I meant by what I was saying. Unfortunately, that happens all too often to many of us. If I had taken the time to write the messages "properly" the thread would have been lost. You are obviously a well learned individual (I suspect a professor of some sort) and I don't mean to "fly in the face" <pun intended> of sound principle. However, I think some "theories" should be thrown out the window. <more pun intended>
Aside from our differences on some aspects of flying, what happens when an RC airplane deploys its flaps? It it because of lift, or push? <big grin> Thanks. <to bad you live so far a way, it sounds like it would be great to sit down over a "pint" and get to the root of the problems of this world! :-). I do love a challenging discussion.