An airplane is provided. The airplane includes a motor-driven compressor assembly. The motor-driven compressor assembly includes a shaft, a motor, a compressor, and a turbine coupled to the compressor via the shaft. The motor provides a first power to the compressor via the shaft. The turbine receives and expands a second medium to provide a second power to the compressor via the shaft. The compressor receives and compresses a first medium in accordance with the first power provided by the turbine and the second power provided by the motor.