Unmanned aerial vehicles allow rapidly deploying a multihop communication backbone in challenging environments with applications in public safety, search and rescue missions, crowd surveillance, and disaster area monitoring. Due to environmental obstructions in the above scenarios or intentional jamming, the communication links between peer unmanned aerial vehicless are susceptible to outages. This necessitates resiliency measures to be closely integrated into the network design. To address the needs of efficient and robust end-to-end data relaying, we propose an aerial network management protocol built on top of an SDN architecture. Unique to our design, each unmanned aerial vehicle becomes an SDN switch that performs under directives sent by a centralized controller. Using a novel 3D spatial coverage-related metric, the controller calculates diverse multiple paths among unmanned aerial vehicles so that isolated and localized failures do not interrupt the overall network performance. The controller issues directives to the unmanned aerial vehicle switches through flow entries in Openflow v1.5 protocol for immediate and effective switching to the best available path. Results reveal that the proposed multi-path routing algorithm reduces the average end-to-end outage rate by 18 percent while increasing the average end-to-end delay by 12 percent when compared to the traditional multi-path routing algorithms.