Originally Posted by
AZFlyer
Regarding the top speeds of high speed aircraft like fighters, etc...what is the main limitation to their top speed?
Eventually you run into a heat problem. The X-15 nearly burned part of the tail off on its mach 6.72 flight. Ceramic tiles can withstand higher temperatures than metal, and ablative surfaces do burn but carry the heat away in small chunks. If you still want to use metal, circulating a cold liquid just inside the critical areas can help.