Re: Not British
The SR-71 engines were notorious amongst the pilots for being finicky, temperamental and downright difficult beasts to use. That was largely down to their complexity, since they had to function in a very wide range of conditions from sub-sonic right up to quite a high mach number (the exact details of which are classified). The basic problem they had to solve was how to deal with a supersonic airflow; they did it by slowing the air down to sub-sonic speeds and then speeding it up again inside the engine.
Biting the hand that feeds IT
