An aircraft that includes a fuselage, an electric motor driven propulsion system, and a fuel cell system configured to provide electricity to the electric motor. The fuel cell system includes a fuel cell, a hydrogen tank, an oxygen tank, an air channel, and a cathode switch. The cathode switch being configured to convert between an air mode, wherein the fuel cell operates utilizing air from the air channel, and an oxygen mode, wherein the fuel cell operates utilizing oxygen from the oxygen tank.