A gas turbine engine includes a compressor section including a first compressor, a turbine section including a first turbine and a second turbine, a first shaft and a second shaft, the first shaft interconnecting the first turbine and the second compressor, and a geared architecture. The first shaft is supported on a first bearing in an overhung manner. A performance ratio is between 0.5 and 1.5.

A computer program product contains computer-readable instructions, which, when operated on by a computer, performs the following method. A combination is determined of relative circumferential positions of the individual rotor components associated to a bow shape configuration of the centers of mass along the axially-extending sequence based on geometrical reference values concerning individual rotor components each having a center of mass and configured to be assembled to one another in an axial sequence to form a rotor assembly, the geometrical reference values being stored in a computer readable memory accessible to the computer.

An air conditioning system for an aircraft is provided. The air conditioning system includes a first rotating component and a second rotating component. The first rotating component includes a compressor and a turbine. The compressor pressurizes a first medium. The first turbine receives a mixture of a second medium and a pressurized form of the first medium. The second rotating component includes a fan.

An air conditioning system for an aircraft is provided. The air conditioning system includes a first rotating component and a second rotating component. The first rotating component includes a compressor and a turbine. The compressor pressurizes a first medium. The first turbine receives a mixture of a second medium and a pressurized form of the first medium. The second rotating component includes a fan.

An airplane is provided. The airplane includes a first medium, a second medium, and an air conditioning. The air conditioning system includes a first turbine, a compressor, and a mixing point. The compressor is located upstream of the turbine in a flow path of the first medium. The mixing point is a location at which the first medium mixes with the second medium. The mixing point is downstream of the compressor and upstream of the turbine.

An airplane is provided. The airplane includes a first medium, a second medium, and an air conditioning. The air conditioning system includes a first turbine, a compressor, and a mixing point. The compressor is located upstream of the turbine in a flow path of the first medium. The mixing point is a location at which the first medium mixes with the second medium. The mixing point is downstream of the compressor and upstream of the turbine.

An air cycle machine for an environmental control system for an aircraft is provided. The air cycle machine includes a compressor configured to compress a first medium, a turbine configured to receive second medium, a mixing point downstream of the compressor and downstream of the turbine; and a shaft mechanically coupling the compressor and the turbine.

An air cycle machine for an environmental control system for an aircraft is provided. The air cycle machine includes a compressor configured to compress a first medium, a turbine configured to receive second medium, a mixing point downstream of the compressor and downstream of the turbine; and a shaft mechanically coupling the compressor and the turbine.

An airplane is provided. The airplane includes a compressing device. The compressing device includes a turbine with a first inlet and a second inlet. The turbine provides energy by expanding mediums. The first inlet is configured to receive a first medium of the mediums. The second inlet is configured to receive a second medium of the mediums. The compressing device includes a compressor and a motor. The compressor receives a first energy derived from the first and second mediums being expanded across the turbine during a first mode of the compressing device, receives a second energy derived from the first medium being expanded across the turbine during a second mode of the compressing device, and compresses the second medium in accordance with the first mode or the second mode. The motor provides a supplementary energy to the compressor

An airplane is provided. The airplane includes a compressing device. The compressing device includes a turbine with a first inlet and a second inlet. The turbine provides energy by expanding mediums. The first inlet is configured to receive a first medium of the mediums. The second inlet is configured to receive a second medium of the mediums. The compressing device includes a compressor and a motor. The compressor receives a first energy derived from the first and second mediums being expanded across the turbine during a first mode of the compressing device, receives a second energy derived from the first medium being expanded across the turbine during a second mode of the compressing device, and compresses the second medium in accordance with the first mode or the second mode. The motor provides a supplementary energy to the compressor