An optimal Strategy for Persistent Contrail Avoidance
Scot E. Campbell, Natasha A. Neogi, and Michael B. Bragg
University of Illinois, Urbana, Illinois, 61801
ABSTRACT
Persistent contrails have been recognized as a potential threat to the global climate. This
paper presents a methodology to optimally reroute aircraft trajectories to avoid the
formation of persistent contrails with the use of mixed integer programming (MIP). The
main contributions of this paper are the introduction of a more realistic fuel burn model,
and the implementation of a quadratic cost function. Existing MIP path planning literature
has used a 1-norm approximation of the vehicle acceleration for fuel burn. The fuel burn
model created for this paper is based on aircraft data and engine performance software, and
the fuel burn cost was approximated with piecewise linear, and quadratic functions for
implementation into the MIP. Fuel optimal trajectories for contrail avoidance were created
for each cost function and the results were compared. In addition, differences between the
linear and quadratic cost were investigated with a pathological obstacle field, and the
sensitivity of the trajectory to changes in the planning horizon length and time step size are
presented. For a specific scenario, it was found that persistent contrails could be avoided
with a 2.76% increase in fuel burn.