Abstract: An aircraft propulsion system includes a gas turbine engine; an environmental control system (ECS); and a bleed flowpath from the gas turbine engine through the ECS. A turbine is along the bleed flowpath and a propulsion fan is mechanically coupled to the turbine to be driven by the turbine.

Abstract: An aircraft propulsion system includes a gas turbine engine; an environmental control system (ECS); and a bleed flowpath from the gas turbine engine through the ECS. A turbine is along the bleed flowpath and a propulsion fan is mechanically coupled to the turbine to be driven by the turbine.

Abstract: An environmental control system (ECS) for use with a gas turbine engine has an air cycle system (ACS) and a vapor cycle system (VCS). The VCS has along a vapor compression flowpath: a VCS compressor; a heat donor leg of a VCS condenser; an expansion device; and a heat receiving leg of a VCS evaporator. The ACS has along a bleed flowpath: a bleed air inlet; a primary heat exchanger; an ACS compressor; a secondary heat exchanger; a turbine coupled to the ACS compressor to drive the ACS compressor; a heat donor leg of the VCS evaporator; a water collector; and a heat receiving leg of the VCS condenser.