In this book the authors examine the design, structure, development, history and RAAF service of the S-51 in detail. Many photographs used in this volume have never previously been published. Clear, colour profiles provide a detailed, accurate account of the various colour schemes and national markings carried by this helicopter in RAAF service. A comprehensive modelling section provides additional detail tips for the modeler and reviews available kits. The book is a worthy addition to the modeller’s reference library.