The U.S. Air Force is currently in the process of building an Airborne Network (AN), where the nodes are a set of heterogeneous, highly mobile, Airborne Networking Platforms (ANPs) - such as satellites, airplanes and unmanned aerial vehicles. Mobility pattern of nodes in a mobile network has significant impact on the coverage and connectivity properties of the network. The level of reliability needed for continuous operation of an AN may be difficult to achieve through a completely infrastructure-less mobile ad hoc networks. In an earlier paper, we proposed an architecture for an AN where a set of ANPs form the backbone of the AN. In this architecture, the ANPs may be viewed as mobile base stations with predictable and well-structured flight paths and the combat aircrafts on a mission as mobile clients. In this paper we consider the AN scenario where a part of the network might not be operational due to enemy attack and/or jamming. We consider faults that are spatially correlated (or region-based), that is faults due to an enemy attack are confined to a region. The goal is to design a robust AN so that no matter which region in the deployment area fails and at what time, the surviving nodes of the network will remain connected and be able to communicate with each other. We propose an algorithm that finds the minimum transmission range necessary to ensure network connectivity irrespective of location of the fault region and the time of the failure.