  This work deals with the problem of estimating the turnaround time in the
early stages of aircraft design. The turnaround time has a significant impact
in terms of marketability and value creation potential of an aircraft and, for
this reason, it should be considered as an important driver of fuselage and
cabin design decisions. Estimating the turnaround time during the early stages
of aircraft design is therefore an essential task. This task becomes even more
decisive when designers explore unconventional aircraft architectures or, in
general, are still evaluating the fuselage design and its internal layout. In
particular, it is of paramount importance to properly estimate the boarding and
deboarding times, which contribute for up the 40% to the overall turnaround
time. For this purpose, a tool, called SimBaD, has been developed and validated
with publicly available data for existing aircraft of different classes. In
order to demonstrate SimBaD capability of evaluating the influence of fuselage
and cabin features on the turnaround time, its application to an unconventional
box-wing aircraft architecture, known as PrandtlPlane, is presented as case
study. Finally, considering standard scenarios provided by aircraft
manufacturers, a comparison between the turnaround time of the PrandtlPlane and
the turnaround time of a conventional competitor aircraft is presented.
