SYSTEMS AND METHOD OF OPERATING A FUEL CELL ASSEMBLY, A GAS TURBINE ENGINE, OR BOTH

A method is provided for operating a propulsion system having a gas turbine engine and a fuel cell assembly. The fuel cell assembly includes a fuel cell. The method includes: receiving gas composition data of output products from the fuel cell; and controlling operation of the fuel cell assembly, the gas turbine engine, or both in response to the received gas composition data of the output products from the fuel cell.