Concorde's specs were up to 5000 fpm climb. With some tweaking to the aerodynamics, flight planning and whatnot, I'm sure you could be supersonic 150nm into the

Concorde's specs were up to 5000 fpm climb. With some tweaking to the aerodynamics, flight planning and whatnot, I'm sure you could be supersonic 150nm into the flight instead of 250nm. (same goes for anything else getting up to cruising altitude)