A compass may save your lifeFlying safely in aircraft implies the use of navigation instruments. Among them, the magnetic compass is still a first choice for orientation and it is compulsory in all aircraft. In our increasingly sophisticated but fragile world of global navigation systems and gyroscopic sensors, the compass is especially useful as a back-up: it has high reliability and is likely to survive in harsh electromagnetic aggressions or when all power supplies have failed.How to use a compass correctly?This book examines in detail how the science of geomagnetism is able to promote a correct use of the magnetic compass for navigation. A selected group of specialists met in Ohrid, Macedonia to expose their approaches to the question. Using techniques from Geology, Instrument science, Magnetism, Chaos theory and Potential Fields applied to the Balkan region and surroundings, they put together a roadmap to fully tackle the issue of measurement, analysis, mapping and forecasting of the magnetic declination in support of aeronautical safety.Aircraft safety in the BalkansThe Balkans, like most regions on Earth, experience increasing air traffic. Yet several airplane crashes have been seen in the area some of them unexplained. The division of former Yugoslavia in the early nineties and the abandon of geomagnetic measurements in many parts of the area since then have left the compass users without reliable and uniform magnetic declination data. The Authors have therefore focused their expertise on the Balkan and surrounding countries, considering them as a good candidate for a case study.