This paper presents an experimental procedure for aerodynamic characterization of a delta-wing UAV for model-based navigation applications. We report the design of experiments, aimed to maximize aerodynamic coefficients observability while meeting time constraints requirements, as well as the significance of secondary aerodynamic influences. A functional model, simple yet accurate, is derived from the experiments. We evaluate it empirically in-flight with an offline-implemented navigation solution during GNSSsignal outages, using data exclusively collected from low-cost sensors embedded in a commercially available autopilot. Results showed that the model-based navigation solution produced a significantly smaller positioning error compared to traditional navigation approaches during GNSS outage.