In “Fuel Cells: A Real Option for Unmanned Aerial Vehicles Propulsion” some unclarities were detected in several figures shown in Table 2. To clarify the table, for the Horizon Energy Systems/AEROPAK, the weight (3.5 kg) has been replaced only by the FC weight (0.47 kg); therefore, the FC power density changes from 57.14 W/kg to 425.53 W/kg. Also, the FC power of PROTONEX/ProCore VI is changed from 800 W (peak power) to 280 W (output power), which implies FC power density of 686.27 W/kg.

We provide the updated Table 2.