HIFR is the acronym for Helicopter In Flight Refueling, a real situation that can be used in different ships where a helicopter is unable to land on deck so it has to refuel while flying. In our ship (ESPS Alvaro De Bazan) we usually refuel the helo while it is on deck but you have to train the HIFR manoeuvre too, it is good training for the pilots and also for the crew. It is really spectacular to see ship and helo linked by this "umbilical cord."