A study has been conducted to establish the Mach number limits of noncryogenic fuels used for manned hypersonic cruise missions. This paper specifically presents results for hydrocarbon fuels similar to JP-7. Both heat sink capacity and propulsive energy properties of the fuels are considered. The analysis approach uses an aircraft sizing program to predict aircraft performance and dynamic thermal models of the aircraft and Thermal Management System (TMS) to determine the fuel's ability to meet requirements over the mission profile. Crew station, avionics, secondary power, engine, and aerodynamic heat loads are accounted for in the analysis. The maximum Mach number capability for conventional JP-7 is determined. Thermal properties needed for advanced JP fuels to attain higher Mach numbers are also presented.