Abstract: A propulsion system for use with an aircraft includes a gas turbine engine, an electric power system, and at least one propulsor. The gas turbine engine includes a compressor, a combustor, and a turbine. The electric power system includes a generator coupled to the gas turbine engine to generate electrical energy, power electronics connected to the generator to receive the electrical energy from the generator, and a motor configured to produce rotational energy in response to receiving electric energy from the power electronics. The propulsor is configured to use rotational energy received from the motor of the electric power system to generate thrust for propelling the aircraft.

Abstract: A method is provided of replacing a damaged blade of an integrally bladed rotor assembly including a disc and a plurality of blades extending outwardly from a rim of the disc. The method includes the steps of: removing the damaged blade to leave a blade repair stub projecting from the rim; locating sacrificial supports at the underside of the rim beneath the repair stub, the supports projecting axially beyond the trailing and leading edges of the rim; depositing metal around the trailing and leading edges of the repair stub, the deposited metal, supported by the sacrificial supports, projecting axially beyond the trailing and leading edges of the rim; attaching a replacement blade to the repair stub by linear friction welding; and removing excess deposited metal, upset metal from the linear friction welding, and the sacrificial supports.