The reason the F-104 needs a big engine is for the big speed. Moving that body through the air at very high speeds creates a lot of drag, and that is what thrust overcomes. Try pushing the glider along at those speeds (assuming the structure could hold together) and it too will need an awful lot of thrust. Just draw yourself the standard 4 forces acting on an aeroplane (I am sure they will be shown somewhere on the NASA site) and you see that thrust opposes drag. Lift off the wing is always at 90 degrees to thrust so thrust can never contribute to wing lift. Thrust can contribute to the overall force holding the plane up such as when the aeroplane is inclined upwards but it is still at 90 degrees to the wing lift so it still plays no part in the creation of lift from the wing. In a perfectly vertical climb the wing is at its zero lift angle and produces no lift at all, only engine thrust opposes gravity, but that is not the same thing as lift from a wing. If during a vertical climb the wing is pulled to some positive angle of attack, its lift is not upwards but horizontal, as it is defined as being at 90 degrees to the wing. So by definition it is simply impossible that the thrust generates wing lift. A force of some sort is required to balance drag in order to maintain speed, and speed is required in order to generate lift, but that doesn't make that force the generator of lift. For example, where does a glider get the forward pointing thrust that balances drag? It has no engine to create thrust. It gets its energy, its fuel if you like, from trading height into speed but what creates that forward pointing thrust? Lift! The wing is actually angled slightly downwards so that the lift vector though still at 90 degrees to the wing is poining ever so slightly forward of the vertical. Then in comparison to the fixed orientation of the gravity vector, lift has a vertical and a horizontal component. That forward pointing horizontal component of lift is the thrust that balances drag. Since in any aeroplane in gliding mode the lift is the thrust, then to say that thrust creates lift would mean that lift would be creating lift. That's a circular argument, lift cannot be the creator of itself, so clearly it is false, lift/thrust does not create lift.

H