80% nickel steel alloy, 11% aluminium, and 9% titanium. Using valves instead of transistors meant for easier maintenance in addition to resistance to EMP. [0]

80% nickel steel alloy, 11% aluminium, and 9% titanium. Using valves instead of transistors meant for easier maintenance in addition to resistance to EMP. [0] [0] http://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-25 http://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-25