The increasing deployment of unmanned aerial vehicles (UAVs) and electric vertical take-off and landing (eVTOL) vehicles places stringent reliability and low-latency demands on aeronautical data communications for safety-critical functions. While heterogeneous multi-link architectures with erasure coding are theoretically promising, a practical evaluation is needed to verify their real-world performance benefits against individual public and private networks. This thesis evaluates how a heterogeneous communication architecture, combining a dedicated Air-to-Ground (A2G) network, a public 5G and a geostationary (GEO) satellite link via a fixed-rate erasure coding scheme, can improve communication reliability for representative UAV and eVTOL use cases. The evaluation combines an extensive in-flight measurement campaign using a helicopter on realistic eVTOL flight trajectories with a subsequent, validated simulation-based analysis to explore architectural optimizations. The in-flight measurements demonstrate that the dedicated A2G network provides a significantly more stable baseline than the volatile public 5G link, and their combination enhances reliability by up to 40 percent compared to single-link operation. Nevertheless, the stringent reliability requirements were not met, with simulations indicating that the integration of a Low-Earth Orbit (LEO) satellite link is a key enabler for filling terrestrial coverage gaps and further boosting performance. The primary conclusion is that while software-based optimizations like erasure coding provide scheduling benefits, the number and diversity of integrated physical links are the most critical factors in achieving the high levels of reliability required for future aerial connectivity. This suggests that future efforts should focus on deploying dedicated aerial networks and integrating diverse technologies, particularly LEO satellite systems, to ensure robust connectivity. A limitation of the study is the assumption for the single- vs. multi-link performance comparison, that the fragmentation of an IP packet into two smaller packets at the source has no effect on its delay and loss once reassembled at the destination.