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UK Civil Aviation Regulations

These are published by the CAA on our UK Regulations pages. EU Regulations and EASA Access Guides published by EASA no longer apply in the UK. Our website and publications are being reviewed to update all references. Any references to EU law and EASA Access guides should be disregarded and where applicable the equivalent UK versions referred to instead.



Bowtie is a visual tool which effectively depicts risk providing an opportunity to identify and assess the key safety barriers either in place or the ones lacking, between a safety event and an unsafe outcome.

Bowtie models are a key component of Performance Based Regulation (PBR) and support:

  • An enhanced, graphic representation of risk.
  • A balanced and cross domain risk overview for the whole aviation system between internal and external stakeholders (including third party risks and exposure).
  • An increased awareness and understanding of the safety risk leading to the ‘Key Risk Areas as stipulated by EASA
  • The comprehensive and wide-ranging practical guidance material for safety risk management at an operational and regulatory level.
  • An identification of critical risk controls and an assessment of their effectiveness.
  • An identification of SPIs to monitor performance of risk control.

Bowties can also be used for a variety of tasks as shown below: (You can download this diagram as a PDF).

What does the bowtie show?