On 19 Mar, 07:45, Jim White wrote:
Having read all 170 posts in this thread I am still happily ignorant of the
theory of flight!

Aircraft stay up because they're afraid of the ground.

That said, you might find it interesting to get hold of the TV
programme and video which the Open University made on gliding
mathematics some years ago. The course in question, "MST207 Applied
Mathematics" is defunct, but a fair number of copies of the AV
material lurk around gliding clubs.

Ian