Anonymous ID: 98ef5c Dec. 24, 2018, 1:36 p.m. No.4454851 🗄️.is 🔗kun >>4454810 >>4454773 >only twice as fast as an F-16. more than about mach 3.5 or so, conventional aircraft materials cannot stand the heat stress. hypersonic is whole nother realm of exotics.