Unmanned aerial vehicles (UAVs) can be deployed and managed in a variety of applications with the help of flying ad hoc networks, or FANETs. However, the dynamically changing topology in FANET has raised significant challenges, mainly related to the insurance of security as a required service for the optimal performance of FANET networks. Blockchain technology has recently been used as an innovative solution to improve FANET security, due to its main characteristics such as transparency, decentralization, and tamper-proof nature. In this poster, we detail some current applications of Blockchain to secure FANET including military, surveillance, and Industry 4.0 services. Finally, we discuss some of the common issues associated with the application of Blockchain on FANET networks.