TSK' 13 125 12 1.15 15 Specific Thrust vs. Various Mach Numbers & Altitudes 145 3.4 2.1 02 0.4 0.5 Mach Number 06 Figure 4:Specific thrust vs. Mach numbers at various altitudes TSFCK/VKN) 01:56 0.054 0.052 605 0048 6.040 Specific fuel Consumption vs. Various Mach Numbers & Altitudes 03 04 0.5 06 07 Mach Number Figure 5: TSFC vs. Mach numbers at various altitudes -250 As shown from those figures above, it's clearly that the maximum specific thrust pointing at the highest altitude at each Mach numbers. Additionally, the Mach numbers increases as the specific thrust decreases. Mainly, it means that this engine will fly at low speed where it approaches to stall velocity. In case of thrust specific fuel consumptions, it increases as the Mach numbers increases. In other word, lower TSFC will reach to higher altitude. As mentioned in propulsion course, that's happened because at high altitude will cause to lower temperature, pressure as well as the density. By that, at the highest altitude less energy will burn.