The problem under discussion is one which concerns both aircraft and engine constructors to an equal degree. Yet although their interest in it is a common one, inevitably their viewpoints will be different. This is not to say, however, that their conclusions will clash, and I want to make it clear that in setting out my views, as those of an engine designer, I intend them to be complementary to those of Mr. Chaplin, with the hope that taken together, they will in so me measure help in leading towards a complete solution of the problem.