To amplify the sentiment a little bit: the guy who invented winglets did so based on physical intuition, not calculation. https://en.wikipedia.org/wiki/Richard

To amplify the sentiment a little bit: the guy who invented winglets did so based on physical intuition, not calculation. https://en.wikipedia.org/wiki/Richard_T._Whitcomb https://en.wikipedia.org/wiki/Richard_T._Whitcomb He was such an intuitionist that AFAICS he apparently spent some of his last years on perpetual motion machines (i.e. some kind of quantum zero-point energy device.) The idea that it's not OK to have spirited discussions about this, that the science should dictate who is right and who is wrong, is just inadequate to the problem. The design space for aircraft is huge, and almost any conceivable practical technique or configuration is going to be conventional, based on experience.