An aircraft includes a thermal management system that is configured to cool portions of the aircraft. The thermal management system includes at least one reverse air cycle machine (RACM) mounted on an engine of the aircraft, and a vapor cycle system (VCS) that is configured to cool the portions of the aircraft. The VCS circulates a refrigerant therethrough. A condenser couples the RACM(s) to the VCS. The RACM(s) coupled to the condenser provides a heat sink for the VCS.