Preface to Second Edition
The original Basic Helicopter Aerodynamics was conceived and written by Dr John Seddon. It found a respected place in the subject of rotary wing aircraft and has informed many. Sadly John Seddon has since passed away and I was very flattered to be asked to revise his manuscript for a second edition. This brought an immediate problem. Do I strip the work down to nuts and bolts or do I revise it as it stands but add my own contributions? Since the book is now under joint authorship, it would have been unfeeling to have pursued the former option since the original concept of John Seddon would have disappeared. For that reason I decided to pursue the latter option of revising the text and adding to it – particularly in the field of illustrations. The design, manufacture and operation of the helicopter rotor tend to be rather esoteric for the newcomer and long textual descriptions can be dry and not helpful. I have added, therefore, a substantial number of images to illustrate and clarify the discussions.
The original diagrams were created by hand, which did not altogether succeed. Since that time, computer technology has improved greatly and the book’s graphics have been updated accordingly. The book’s size has increased to allow for the additions but I have been mindful of the need to retain the compactness of the original work.
Helicopter rotor aerodynamics continues to be investigated. It is essential to introduce recent developments to the student and I intend to maintain this book in a form that will introduce the latest developments. While an introductory text cannot hope to describe new techniques in detail it must be capable of establishing the correct thoughts in the reader’s mind, thus preparing them for more intensive study.
The revisions have been aimed at illustrating, more fully, the various features of rotor aerodynamics and helicopter design. The helicopter is unique in its linking of the aerodynamic and mechanical features and a full appreciation of these air vehicles can only be achieved by understanding these interactions. Many of the extra figures illustrate the diversity in the design and operation of a helicopter and these differences are highlighted in the text.
As with all things aeronautical, a team effort is always needed, and the assembly of this book is no exception. A picture says a thousand words so I have called upon the skills of many people to provide as many photographs as possible to amplify and, hopefully, clarify the explanations. While I have been able to supply a number of these photographs personally, a considerable number have been kindly supplied and I would like to sincerely thank the following people for their generosity. Denny Lombard of Lockheed Martin, Alan Vincent, Alan Brocklehurst and Alan Jeffrey of GKN Westland Helicopters, Harry Parkinson of Advanced Technologies Incorporated, Stewart Penney, Guy Gratton, David Long of Kaman and Steve Shrimpton.
While I am quite pleased with my own photographic attempts, I am mindful that the pictures were taken on the ground, usually on a pleasant warm day with plenty of time to press the shutter release. In contrast, the above mentioned people have obtained better quality results while often hanging out of an aircraft in very difficult situations. This marks the difference between the amateur and the true professional.
I would also like to thank my colleagues and researchers who have provided much thought provoking discussion, which I hope, is reflected in the book. I am very grateful to David Balmford for his suggestions in correcting the text. I also would like to express my thanks to Ian Simons for his constant advice on all matters aeronautical. I offer many thanks to Julia Burden at Blackwell Science for her forbearance. The manuscript was late and she stuck with it, probably biting her lip but giving me valuable support. She offered me the task of revising the book and I hope she is not disappointed.
Finally I would like to thank my wife, Stella, for putting up with my constant whizzing around putting the final touches to this work, snatching a cup of coffee as I speed by.
Simon Newman Winchester January 2001