It is a great honour and pleasure to be invited to deliver this Lawrence Hargrave Memorial Lecture in my home town—particularly as it gives me a chance to pay tribute to a man whose contributions to the development of the science of flight are commonly overlooked and usually under-rated.

I can remember vividly Professor Stephens delivering the first of these Memorial Lectures in 1956. With his whimsical sense of humour he started in a rather unconventional way. Without any of the usual introductory words he flashed a portrait of Lawrence Hargrave on the screen and said “Well, there he is—a handsome fellow—what you can see of him.” In a sense these words sum up the theme of my lecture. I want to discuss some of the outstanding problems of the international airline industry—an industry whose handsome features are at present somewhat obscured by adversity.