Unmanned Aerial Vehicles (UAV) are emerging as a powerful tool in various industrial applications in the context of enabling Industrial IoT. The limited power source and flight time of UAVs along with the need for skilled UAV operators are some of the most daunting challenges to the integration of UAVs in industrial applications such as site inspection, workforce monitoring, logistics, and others. In this article, we propose the unique paradigm of AerialBlocks for blockchain.enabled UAV virtualization to provide virtual UAV-as-a-service for industrial applications. AerialBlocks also aims at providing secure and persistent UAV services to the end-users along with a partially decentralized blockchain model to ensure security, privacy, service quality, and transparency. UAV virtualization allows persistent UAV services, globally, without procuring any physical UAVs. The platform offers virtual UAV services on a pay-per-use basis to the end-user. The UAV owners and virtual UAV service providers gain monetary benefits for their contribution to the UAV service offerings. Finally, we discuss the implications of the proposed platform on the domains of Industrial IoT and the possible challenges in the implementation of this paradigm.