PURPOSE 

To ensure the safety of aviation, it is necessary that aerodrome lighting has a high level of integrity and reliability. It is considered that the probability of failure of well-designed and maintained lighting at a critical moment is extremely low. 

The following material is intended as a guide to the recommended electrical engineering practices for design and installation of new systems and the modification of existing systems of aerodrome fixed lighting. It does not imply that existing installations, if different, are wrong and should be changed automatically. It does mean that some of the earlier designs adopted are not recommended for repetition since they have been superseded by later designs. Because of the differences in engineering style and equipment in different States, this material is intended to indicate basic design principles. It is not intended to illustrate detailed design or particular pieces of equipment or systems unique to any one State. 

The electrical systems for aerodrome visual aids require good quality installations and consideration for features which are not usually involved in other electrical installations. This manual examines the general features of electrical practices and installations with emphasis on those features which are less commonly involved or have special significance for aerodrome operations. It is assumed that those using this manual will be familiar with electrical circuits and general practices, but may not be knowledgeable of certain features of aerodrome series circuit installations, which are less frequently encountered in other electrical systems. Some of these features are that most electrical circuits are installed underground, series circuits are used for most lighting systems, higher reliability is required of the input power sources, and rapid, automatic transfer to secondary power in case of power failures. Each aerodrome is unique, and its electrical installation should be designed to provide economical power and control which is safe, reliable, and easily maintained.