Abstract: An air cycle machine (ACM) pack system for an aircraft with an improved low inlet pressure cooling performance is provided. The ACM pack system has an air cycle machine (ACM) with at least one compressor mechanically coupled to at least one turbine in series on an ACM shaft. The ACM pack system further has a pack heat exchanger coupled to and in fluid communication with the at least one compressor of the ACM. The ACM system further has a bypass air flow assembly coupled in a parallel operation path to the ACM and has a bypass air flow regulating element. The bypass air flow assembly transfers energy extracted by the bypass air flow assembly to the ACM to aid the ACM pack system in cooling performance at a low inlet pressure, resulting in an improved low inlet pressure cooling performance of the ACM pack system.

Abstract: Systems and methods for sensing gas are disclosed. In one aspect, a system to monitor an output of a gas source comprises a chamber comprising a plurality of input ports to receive inputs from a plurality of gas sources, and means for repeatedly blocking one of the plurality of input ports for a period of time, detecting which one of the plurality of input ports is blocked, collecting data from a plurality of samples from the enclosure while the one of the plurality of input ports is blocked, and storing the data in a memory in association with an indicator of which one of the plurality of input ports is blocked. Other embodiments may be described.

Abstract: An air cycle machine (ACM) pack system for an aircraft with an improved low inlet pressure cooling performance is provided. The ACM pack system has an air cycle machine (ACM) with at least one compressor mechanically coupled to at least one turbine in series on an ACM shaft. The ACM pack system further has a pack heat exchanger coupled to and in fluid communication with the at least one compressor of the ACM. The ACM system further has a bypass air flow assembly coupled in a parallel operation path to the ACM and has a bypass air flow regulating element. The bypass air flow assembly transfers energy extracted by the bypass air flow assembly to the ACM to aid the ACM pack system in cooling performance at a low inlet pressure, resulting in an improved low inlet pressure cooling performance of the ACM pack system.

Abstract: Systems and methods for sensing gas are disclosed. In one aspect, a system to monitor an output of a gas source comprises a chamber comprising a plurality of input ports to receive inputs from a plurality of gas sources, and means for repeatedly blocking one of the plurality of input ports for a period of time, detecting which one of the plurality of input ports is blocked, collecting data from a plurality of samples from the enclosure while the one of the plurality of input ports is blocked, and storing the data in a memory in association with an indicator of which one of the plurality of input ports is blocked. Other embodiments may be described.