• An Airspace Infringement (AI) is the unauthorised entry of an aircraft into notified airspace. Around 1,200 are reported to us each year from most parts of the UK by Air Navigation Service Providers (ANSP) through the MOR (Mandatory Occurrence Report) process.

    UK airspace can be complex, and many factors can contribute to an individual infringement. But every infringement has the potential to cause a significant safety risk. So it is important that all infringements are reported and subject to the same process, regardless of the apparent immediate effect. A pilot, for example, may not be aware of the knock-on effect an infringement may have to air traffic control or other aircraft. 


    When we receive these reports, we must investigate the circumstances of each one and determine whether lessons can be learned, and whether action can be taken to prevent or reduce future events.

    It is up to each ANSP to first internally review every infringement before reporting it to us as an MOR if the circumstances dictate it.

    Around 95% of all incidents are processed through our review and actions process set out in CAP 1404. 

    CAP 1404 has been amended to highlight the CAA’s audit and safety assurance functions of the Infringement Co-ordination Group (ICG), and introduces the option for those provisionally suspended by the CAP 1404 process to request a review of that decision. These changes take effect on 2 August 2021. As well as this new review process we are continuing to assess other options for stakeholders to have certain CAA decisions reviewed, in line with our new regulatory principles.

    Read more about our Airspace Infringements: review and actions process (CAP 1404).


    We follow and promote Just Culture throughout all our work.  So our investigations seek to establish the facts to fully-understand why an incident occurred and what remedial training/education actions can be taken to prevent a repeat. Our aim is to promote continuous learning from previous mistakes and to encourage pilots to openly and freely share essential safety related information. 

    Guidance and statistics 

    The Airspace & Safety Initiative is a collaboration with  NATS, AOA, general aviation groups and associations and the Ministry of Defence to tackle safety risks in UK airspace. The website includes guidance, resources and regular occurrence narratives which share lessons to help avoid future infringements.

    We publish monthly statistics of reported infringements by airspace and aircraft type and a summary of airspace infringement team decisions. The site also includes annual summaries of reported infringement statistics (from 2017) and causal factor analysis reports. Read more about reported infringement statistics.