Aviation Dictionary

On this page you will find a searchable and comprehensive alphabetical list of aviation terms. You can help us make it the most comprehensive list in the world. If we have missed anything, click on the ‘send us your word’ button to send us your word, acronym or definition and we will consider adding it to our dictionary.

Go back


A device that has a magnetic needle which will point to Magnetic North. In aircraft, a compass can experience variations due to interference from the electrical system and other components within the aircraft and a deviation card can be found which will give the correction for any errors. In the Southern Hemisphere, ONUS is used for compass turns, ONUS being : Overturn North Underturn South

7 Day



Get access to the complete catalogue of your chosen subscription level for 7 days. After your free trial, your paid subscription automatically commences. Cancel anytime.

Get FREE Trial


Do you want to be notified each time we upload informative new content to this site? Just enter your email address below to subscribe and receive alerts.