Volume 4 takes you through the entire subject, starting with Radio Principles and progressing to more advanced topics such as General Radio Procedures, Communication Procedures at Aerodromes, Emergency Procedures and a host of other topics. Communication in aviation is a cornerstone of flight safety. Without the ability for pilots and Air Traffic Controllers to communicate in clear and unambiguous terms, the environment would be a very dangerous place indeed. Clearly, there need to be internationally accepted procedures and techniques that standardise the manner in which communications are handled, these standards are set by the International Civil Aviation Organisation (ICAO) with its headquarter in Montreal, Canada. This manual complies with ICAO and New Zealand regulatory requirements. English is the official language used in worldwide aviation. This aspect, in addition to the ICAO agreed procedures and terminology, make this book a useful reference in many countries even though some may have minor variations to suit local conditions.