Airspace Rules

Airspace Classes

All controlled airspace (ICAO Classes A-E or equivalent) should be displayed where possible.

Uncontrolled airspace (ICAO Classes F & G or equivalent) should not be displayed unless one of the following applies:

• The airspace underlies or is part of an Oceanic sector (OCA).
  • Mark clearly as Class G.
  • If airways assume a different class, include that class, as well.
• The FIR uses blanket controlled airspace at very low altitude (e.g. Class E in the USA)
  • Include Class G airspace in the sector.
• The FIR has blanket radio-mandatory status (e.g. Australia).
  • Include Class G airspace in the sector.
• Controlled airspace exists but has two bases - one at an altitude or flight level, relative to sea level (AMSL), and another at a height, relative to ground level (AGL).
  • Define the sector using the altitude base.
  • Do not include the height base.
• Radio/Transponder Mandatory Zones.
  • Mark the airspace as a Class G RMZ/TMZ.
  • Equivalent national classifications (e.g. TIZ, TIA, ATZ) may be used.

Do not include FIS/Information/Advisory sectors, unless the airspace meets one of the above conditions.

Sector Drawings

Try to avoid overlapping sectors, where possible. If multiple controllers share a single airspace block (e.g. Copenhagen Approach & Departure or London Terminal NW), assign the sector to one controller only.

In some areas (e.g. Greenland), overlaps between local ATC and an overlying sector may be beneficial.

Time Restrictions

To simulate time-limited controlled airspace and ATC sector boundaries, use the fua property for the relevant sectors.

Sectors will not display on the main site or the /all page outside of their operating times.

To simulate airport opening/closing times for top-down service, use the time property for the relevant airports.

Airports will not be assigned to overlying controllers outside of their operating times. Airports will still display as controlled if local ATC is online.