News Safety

Health Risk Bow Tie Model

The article is written by Mr. John Franklin (EASA).

This article and the attached bow tie files are intended to help anyone working at an airport or airline who is implementing COVID-19 health measures as part of the EASA/ ECDC Aviation Health Safety Protocol (AHSP).

The purpose of the Bow Tie Model

These bow ties were developed to Map the risk of Covid-19 transmission through the transport of passengers, during their journey through the airport and on the aircraft. It can be used by you to understand your risks as an organization, it has also been used as a resource by EASA to ensure that the AHSP is complete, and to develop a monitoring framework for the implementation of the AHSP.

Bow tie models are used to understand risks, they are a useful way of visualizing a risk and developing mitigating actions. They help users to clearly identify the “top event” that they wish to prevent, the threats that may lead to this event and the consequences. Once these are in place, preventive barriers can be identified, in order to reduce the severity or likelihood of the top event. Recovery barriers can also be identified, to reduce the severity or likelihood of the consequences. The barriers can be categorized according to the type of mitigating action, for example how effective it is or whether it is a behavioural, socio-technical or hardware related barrier. Each barrier can also have “escalating factors”, which describe threats to reducing the effectiveness of the barrier, and these escalating factors in themselves have barriers.

Scenarios/ Top Events Covered in the Bow Tie

The bow tie has been set up to cover the most common types of COVID-19 transmission that are likely to occur during the normal passenger’s journey through the departure airport onto the aircraft and out of the arrival airport at the other end. It covers the following situations with barriers (mitigations), types of barriers, and their effectiveness in limiting the spread of the virus.

–           Member of the public spreads the virus onboard the aircraft.

–           Member of the public spreads the virus at the airport.

–           Airport staff spread the virus.

–           Aircrew spread the virus onboard the aircraft.

–           Suspected case during the flight.

–           Ground crew spread the virus through contact with other people.

–           Ground crew spread the virus through surface contact.

–           Contaminated aircraft surfaces.


Read full article on EASA website:

Inxelo Technologies provides option to import this BowTie diagram into ICARUS software to its customers.



Mr. John Franklin (EASA)

About the author

Inxelo Technologies

Inxelo Technologies Ltd. is a company that core-business is software development in aviation industry.
Our mission is to provide quality software solutions to any air operator and improve their operations.
The software solutions we create for our customers are in various fields in aviation such as safety management system and compliance management system.