• Airspace change proposals vary greatly in terms of size and complexity. For example, a minor change to the boundaries of high-altitude airspace over the sea will be significantly different to a major reorganisation of flightpaths at lower altitudes or over a built-up area near airports.

    The airspace change process must therefore be sufficiently scalable to accommodate different types of proposal: not all airspace change proposals necessarily need to be subjected to every element of the process. Proposals are therefore assigned a Level depending on the characteristics of the change, to which the requirements of the process are applied proportionately. This scaling applies only to permanent changes to notified airspace design.

    The table below describes each Level. Detailed information on each Level and the way in which requirements are scaled is available in CAP 1616 - Airspace Design: Guidance on the regulatory process for changing airspace design including community engagement requirments.

    Level   Description
    Level 0 All

    Level 0 changes are changes to nomenclature or qualifying remarks of notified airspace design that will not alter air traffic patterns.

    Change sponsors are required only to complete Stage 1A of the airspace change process.

    Level 1 All

    Level 1 changes are high impact changes to notified airspace design which have the potential to alter traffic patterns below 7,000 ft over a populated area.

    They are typically large-scale changes which alter aircraft tracks or dispersion, or reduce aircraft height over land below 7,000 ft over a populated area. Examples include changes to departure or arrival routes at airports and changes which have a significant impact on other aviation stakeholders.

    Level 2 All Level 2 changes are medium to low impact changes to notified airspace design which do not have the potential to alter traffic patterns below 7,000 ft over a populated area.
    2A Level 2A changes are typically those which alter aircraft tracks or reduce aircraft height over land below 20,000 ft and at or above 7,000 ft. Examples include changes to Air Traffic Service routes and the establishment of new controlled airspace below 20,000 ft.
    2B Level 2B changes are typically those which involve controlled airspace over the sea; controlled airspace at or above 20,000 ft; or are outside controlled airspace at or above 7,000 ft.
    2C Level 2C changes are typically those which do not alter traffic patterns below 7,000 ft and either reflect current use of the airspace concerned or involve the removal of an established airspace structure.
    Level M All Level M changes are those sponsored by the Ministry of Defence where the CAA is required to disregard the potential environmental impact of the change when reaching its decision on whether to agree to the change to airspace design. We do, however, continue to take into account the potential environmental impact of affected civil operations resulting from the proposed change. Some Ministry of Defence changes do not require CAA permission or approval.
    M1 Level M1 changes are those where an anticipated consequence of the proposed change is an alteration of civil aviation traffic patterns below 7,000 ft. They are treated similarly to Level 1 changes (above).
    M2 Level M2 changes are those where an anticipated consequence of the proposed change is either an alteration of civil aviation traffic patterns at or above 7,000 ft or no impact on civil traffic. They are treated similarly to Level 2 changes (above).


    All heights cited are above mean sea level.