- National Jet Systems is an Australian charter airline that operates a fleet of various aircraft models, including Embraer ERJ-135 and ERJ-145 regional jets. The airline primarily offers charter and contract services, including fly-in fly-out operations for resources and mining companies, as well as ad hoc charters for corporate and government clients. National Jet Systems is a subsidiary of the Regional Express Holdings Limited (Rex) Group, which also operates the Regional Express Airlines (Rex) brand.