Large-scale airborne networks, which connect airborne nodes with high-bandwidth communication links are being actively pursued commercially . We propose utilizing thousands of operational passenger and cargo aircraft as the principal components of an airborne network which could provide high-speed Internet to passengers on-board and on the ground. To simulate such a network we have augmented the ns-3 network simulator with a model for ingesting and processing aircraft position information, a steerable directional antenna model, a wireless point-to-point channel and associated net devices, and a distributed topology control application to manage the topology of the mesh network. We describe our implementation of these models and some tools for visualizing airborne networks. Using a simulation of a large airborne network, covering the United States, we perform experiments to evaluate the effectiveness of using the Optimized Link State Routing Protocol (OLSR) to route network traffic. Our simulations lead us to conclude that OLSR is likely not a good fit for our envisioned network.