well we can differ, an engine failure is in most twin engined types an emergency action, RED and therefore a mayday. We as crew don't know for sure what is going on in there and in any case unless you declare an emergency no-one else on the ground is at high alert. Should it become a full blown emergency you really want everyone prepared. An abnormal is in my opinion something like a cracked windscreen that requires a level change and a reduction of cabin pressure, should it fail completely then its an emergency.