The rate of change in the field of avionics is so fast that even the legislators are struggling to keep up with it. With new digital cockpits, it is getting to the stage that, if your VCR still flashes 12:00, you will have no business flying a modern helicopter The majority of twin-engined (and many single-engined) aircraft now have complex autopilots, glass cockpits and navigation equipment, possibly including Flight Management Systems (FMS). This book originated with a request from the RCAF for training materials for engineers, but curious pilots whose training syllabus did not include avionics, and who would like to know a little more will find it useful as well.