Concorde used turbojet engines, with afterburners for takeoff and from M0.95 to M1.7 Boom is using medium-bypass turbofan engines which are much more efficient

Concorde used turbojet engines, with afterburners for takeoff and from M0.95 to M1.7 Boom is using medium-bypass turbofan engines which are much more efficient. As for comparison with the F-22, The F-22 engines are quite reliable. The F119 engine (to my knowledge) has never had a core failure requiring shutdown in flight. The RAM (Radar Absorbent Material) coating on the F-22 is maintenance intensive, but not required for a SST. Almost 50 years of research should provide a paint that can handle the heating of supersonic flight, with minimal maintenance.