• Air Traffic Controllers can report an Alleged Breach of Air Navigation Legislation (ABANL) by completing the CA 939 form

    Examples of when a report may be required include, but are not limited to:

    • infringement of controlled airspace
    • low flying
    • failure to comply with ATC instructions

    Please email the completed CA939 form to iet@caa.co.uk or return it by post to address shown on the form.

    Please note that the CA939 form is only for use by Air Traffic Controllers

    Guidance for members of the public on how to report a potential breach of aviation law 

    Making a report

    Please ensure that the event is described with as much detail as possible. 

    Reports should include the following information where appropriate:

    • the identification of all aircraft involved together with relative tracks and times
    • any loss of separation associated with the ABANL
    • a statement as to the degree of actual impact the event had on ATC operations including any tactical avoiding or delaying action taken by ATC 

    Detailed guidance for Air Traffic Controllers wishing to report an ABANL is available in Section 6 of CAP 493.