Most of the items I've read here are all about sub-sonic aircraft. Anything that goes beyond about MACH .9 has a very diferent design, to reduce drag. because the faster you go to the sound barrier, the more power it takes. So if you want to have a decent payload, you must keep your drag down. This will allow you to have a smaller engine, less fuel burn. Also the design of the intake is a very critical item, and must be designed to prevent shock waves from entering the engine. Most super sonic A/C still use the area rule, giving the apearance of a coke bottle.
Back to engines designed to come off, the engines on most of the early Boeings were designed to do this. The 737 has to forward mounts that are made with a rubber disk and a cone bolt designed to rotate if the engine creates a runaway. the aft mount is also a cone bolt, and they are all designed to shear if too much strain is put on them. There is also a secondary mount made of either a small wire, or later ones have a crushable disk in it.