The COVID-19 pandemic has severely restricted global air travel and brought into focus the risk of infection during travel in the aircraft cabin. In response to this issue, the passenger flow simulation PAXelerate 1 developed at Bauhaus Luftfahrt was extended to include an assessment of individual passenger COVID-19 exposure risk during the boarding process 2 .

The basic modelling consists of tracking all passenger movement in the cabin during boarding, determining proximity to other passengers, and monitoring the duration and number of individual contacts. This approach is similar to the framework introduced by Apple and Google for contact tracing on smartphones. Analysis of the data for a two-aisle medium-haul aircraft (252 PAX) indicates an increased exposure risk for scenarios involving sorted back-to-front or front-to-back boarding. Boarding scenarios such as window-to-aisle, a random sequence, or the so-called Steffen procedure, on the other hand, appear to be beneficial. Conventional class-wise boarding is used as a reference in each case. In general, advantages are visible for sorting sequences in which the number of interactions and congestion situations is reduced.

The results of the evaluation allow for future adaptation of the currently applied procedures and contribute to the normalisation of international aviation.

Seat-dependent exposure risk

Visualisation of the distribution of the various parameter values for a passenger depending on the seat during boarding. The access door is located at the bottom left of each graph [2].

Model parameter overview

Average values for the various risk parameters depending on the boarding strategy selected. The advantageous values for a baggage-free or optimally distributed boarding sequence are striking [2].

In PAXelerate, other passengers in contact proximity are registered at each time step.

1 PAXelerate is available open source at
2 Engelmann, M., & Hornung, M. (2021). Boarding Assessment and COVID- 19 Considerations for the AVACON Aircraft Cabin Concepts. Deutscher Luftund Raumfahrtkongress 2021, (p. 9). Bremen. doi:10.25967/550012