The world moves quickly, and so does the aviation industry. Airspace structure is revised, routes are changed, and aerodromes change with them. As such, all of the information in the AIP has to be regularly updated. This is done via AIRAC; a standardised system that ensures all updated information is correctly advertised, that all relevant people are able to see the updates, that the regularity of updates is maintained, and most importantly that everyone sees the same data.
Updates to the AIP are made every 28 days. These periods are referred to as AIRAC cycles. Every 28 days the AIRAC cycles changes, and so does the AIP. There are usually 13 AIRAC cycles each year. These cycles are given a 4 number code, which can be easily identified; the first two numbers correspond to the last two numbers of the year (i.e. 22 for 2022), and the last two numbers correspond to the number of the cycle in the year (i.e. 2206 for a cycle effective 16th June 2022). The effective dates of AIRAC cycles 2020-2024 can be found below.
The Division also releases a new sector file for use on the Network, usually with each AIRAC cycle. It is recommended all controllers use the most up-to-date sector file available, as others may be missing crucial updates/revisions.