https://www.theregister.co.uk/2019/10/22/reaction_engines_precooler_demo_mach_5/

Brit rocket outfit Reaction Engines has demonstrated its precooler chilling air in Mach 5 conditions in less than 1/20th of a second.

In context, Mach 5 is more than twice as fast as the Concorde's cruising speed and 50 per cent up on the SR-71 Blackbird.