In article .com,
"Tony" wrote:

If I'm reading this right induced lift for constant area is inversely
proportional to span, and goes up linearly with area.

At more or less constant chord, area is linear with span, so the idea
would be to have chord go down as span goes up. I'd guess e starts
changing as the wing grows too slender.

That pretty much gives me what I wanted to know. I'd guess higher order
terms have to come into play with increasing airspeed.

Thanks

Tony

Only partially correct. Induced drag goes up inversely with the square
of span, and directly with area.

The efficiency factor, e, is a lift distribution (wing shape) factor,
being, theoretically, 1.0 for a wing with elliptical lift distribution
and reducing in magnitude for tapered distributions and constant chord.

Bear in mind, e can be tricked into higher efficiencies by varying the
angle of incidence or changing the airfoil shape from root to tip, so it
*may* not represent an elliptical planform.

Flutter problems may arise with wings that have long spans and narrow
chord, so everything you do is a compromise.