In the civilian world a air test is not required after a engine change, what is required is a full power run to ensure all parameters EPR/N1 ,EGT ,vib levels etc etc are all within the normal limits and that all associated systems are functioning normally, of course that does not mean a company could make a air test a "company requirement" but ive never heard of it, the only thing there normally interested in is getting it back into service asap