Topological Robustness in Formation Flight: A Sensitivity Study

In long-haul aviation, formation flying is a promising strategy to reduce fuel consumption by leveraging aerodynamic upwash. Finding optimal flight plans is a complex hybrid optimization problem, involving both discrete decisions (the sequence of aircraft groupings and separations) and continuous variables (rendezvous and breakaway coordinates). While previous research has focused on coordinate sensitivity, this paper investigates the topological robustness of the optimal structure. By analyzing three-aircraft scenarios across diverse trans-Atlantic routes, we evaluate how variations in follower efficiency gains affect the stability of the optimal topology. Our analysis identifies ‘topological plateaus’—parameter regions where discrete flight-plan decisions remain invariant—providing a reliable basis for operational planning under performance uncertainties. Results demonstrate that the core formation segments of the flight plan exhibit significant resilience to variations in efficiency parameters, with robustness being highly dependent on route pairing. These findings offer critical insights for the reliable implementation of commercial formation flight operations.