The general model aircraft scene has changed remarkably since 1978. Very large models have become almost commonplace. Many of them exceed the old legal limitations and have to be specially licensed for flight. Radio controlled helicopters have become reliable and sophisticated. The emphasis on multi-task and cross country flying for model sailplanes has transformed these aircraft beyond recognition, in ways that were only hinted at in the first edition. Every aspect of model design and construction has been profoundly affected by the increasing use of materials such as carbon fibre, Kevlar, and new kinds of adhesives. Radio control equipment now commonly available is extraordinarily precise and highly reliable. Electric and solar powered models flourish everywhere and begin to rival 'glow plug1 engined craft. Further developments in gyroscopic stabilising devices and automatic pilots will make these more accessible in future and there is increasing interest in the development of advanced electronic instruments which will inform the pilot, on the ground, of exactly what his model is doing aloft. Microcomputers, now so commonplace, enable modellers, even without scientific or mathematical training, to design new aerofoil sections and optimise the performance of their aircraft by using commercially available software. Models already fly with small computers on board, not to mention surveillance instruments and cameras.

The need for a new edition of this book became increasingly apparent as the years passed. The bask theory has not changed, but Che author has corresponded with many model fliers in many countries. These discussions have indicated to him some passages which were ambiguous or over-simplified in the original. There have been numerous small improvements of wording in the interests of greater clarity and emphasis. Some chapters have been re-grouped or re-arranged to improve the logical sequence. Many more sub-headings have been added to break up and make more legible what is, inevitably, a fairly solid text.

M.Simons. Model Aircraft Aerodynamics 1994