AIRAC stands for Aeronautical Information Regulation And Control. It is the system ICAO uses so that changes to procedures, frequencies and navigation data all take effect on the same, predictable dates around the world.
The 28-day rhythm
A new AIRAC cycle starts every 28 days, always on a Thursday. That gives 13 cycles in most years and 14 in some. Cycles are numbered by year and order: 2611 is the eleventh cycle of 2026.
Publishers must send out the changes well before they take effect, normally 28 days ahead and 56 days for significant changes, so that airlines, chart makers and database providers can prepare.
Why it matters in the simulator
Your simulator's navigation database has a cycle too. Problems start when the database and the chart disagree:
- A SID on the chart may not exist in your flight computer, or may have different waypoints.
- A frequency may have changed, so your ILS never captures.
- A new runway designation (for example after magnetic variation changes) may not match.
The fix is simple: use charts and navigation data from the same cycle, or at least check the procedures you plan to fly.
How AeroAtlas shows cycles
Every chart on AeroAtlas carries the cycle its publisher stated. We never guess. If a chart's cycle is older than the current one, it is marked Outdated; if the publisher did not say, it shows Cycle not recorded. US charts are refreshed automatically when each new cycle starts.
For flight simulation and training only. Real-world procedures vary by country and operator; always follow the published charts and your local rules.
Keep reading
- How a flight comes together: The order experienced simmers prepare a flight in, from picking a route to closing the door.
- Reading aeronautical charts: What is on an airport diagram, a SID, a STAR and an approach chart, and where to look first.