It will be helpful to explain certain logistics of the presentation. Symbols are defined when first introduced but for ease of reference are also collected in a list at the start of the book. As concerns units, where there is complete freedom of choice the metric system is preferred; since, however, much use continues to be made of imperial units, particularly in the USA, I have also employed these units freely in numerical examples, sometimes giving both. Again there are tables at the start defining primary and derived units and listing the conversion factors. Lastly, on the question of references, these are numbered in each chapter and listed at the end of the chapter in the usual way. Exception is made, however, in the case of six standard textbooks, which are referred to repeatedly, usually for further information on a topic where the present short treatment is deemed to have gone far enough. The books are:
1. Bramwell, A. R.S. (1976) Helicopter Dynamics, Edward Arnold.
2. Johnson, W. (1980) Helicopter Theory, Princeton University Press.
3. Stepniewski, W. Z. and Keys, C. N. (1984) Rotary-wing Aerodynamics, Vols I and II, Dover.
4. Leishman, J. G. (2006) Principles of Helicopter Aerodynamics, 2nd edn, Cambridge Aerospace Series, Cambridge University Press.
5. Padfield, G. D. (2007) Helicopter Flight Dynamics: The Theory and Application of Flying Qualities and Simulation Modelling, 2nd edn, Blackwell.
6. Cooke. A and Fitzpatrick, E. (2002) Helicopter Test and Evaluation, Blackwell.
In the texts, these are called upon by author’s name and no further reference is given.
With this brief introduction we are poised to move into the main treatment of our subject. Finally I would like to mention the following text, which is a source of valuable historical information on helicopters – Boyne, Walter J., Lopez, Donald S. (1984) Vertical Flight – The Age of the Helicopter, Smithsonian Institution Press.
Reference 1. Jones, J. P. (1973) The rotor and its future. Aero. J., 751, 77.