The enigma of flight is how wing can generate large lift L and the expense of small drag D, with the quotient L/D, also called finesse, larger than 10, with L/D = 15 – 20 for common airplanes and L/D = 70 – 100 for extreme gliders.
The following plots display the distribution of lift and drag on the upper and lower side of a wing for angles of attack 0, 2, 4,10 and 18, and thus reveal the miracle:
We observe in particular the following features:
- large lift on top of leading edge
- smaller high pressure below leading edge
- negative drag on upper part of leading edge
- small drag and lift at trailing edge.
which combine to give L/D larger than 10.