Almost all elementary textbook explanations of the theory of flight rely heavily on Bernoulli's principle and the fact that air travels faster over a wing than below it. In recent years the inadequacies and, indeed, fallacies in this explanation have been exposed (see Babinsky's excellent article in 2003 Phys. Educ. 38 497-503) and it is now appreciated that it is possible to provide a much simpler explanation in terms of Newton's laws. In this article it is shown how a couple of plausible assumptions are all that is needed to calculate a lot of interesting facts about wings. (Contains 4 figures.)