Re:United Airlines will buy 15 planes from Boom Supersonic
by masklinn on Thursday June 03, 2021 @11:41AM
(#27383016)
That's basically all fast flying planes. Engines are designed and tuned for cruising speed, not for going up to cruising speed.
The SR-71 was not exactly manoeuvrable or efficient at low speeds, its efficiency range was above M3.
Wiki says: The overall thermal efficiency of the engine in supersonic cruising flight (supercruise) was about 43%, which at the time was the highest figure recorded for any normal thermodynamic machine.
https://en.wikipedia.org/wiki/Rolls-Royce/Snecma_Olympus_593