The U.S. Air Force has formed the 79th Expeditionary Rescue Squadron in Afghanistan. The unit consists of 80 personnel and two HC-130P aircraft, for flying critically ill patients to medical facilities (in Afghanistan or the Persian Gulf) that can handle them. This is a continuation of a trend that began in 2003, and before.
Since combat casualties were first moved by airplane during World War II, the rule was that the patient had to first be stabilized. That meant that patients in need of the most complex intensive care (specialist surgeons, special equipment) would often die because they needed that special care to be stabilized in the first place. In the 1990s, the U.S. Air Force came up with a solution. It's the CCATT (Critical Care Air Transport Team), which consists of a doctor, a critical care nurse, a medical technician and a lot of portable emergency room equipment. Like computer equipment in general, medical gear has become smaller and more efficient. So the CCATT team can basically carry their portable emergency room onto any transport aircraft that is carrying one or more patients in need of specialist care. The medical personnel take care of most medical emergencies while in flight, and the concept has already saved the lives of American troops badly wounded in places like Afghanistan and the Philippines. Iraq, on the other hand, had less need for CCATT because it is a large operation with extensive medical facilities in the area. But even in Iraq, there is sometimes a need to get very badly wounded troops to specialist facilities in Europe or the United States. The three members of the CCATT teams undergo two weeks of training on how to operate an ICU (Intensive Care Unit) in the sky.
In Iraq, it was soon found possible to use KC-135 aerial tankers to carry CCATT teams and their patients. The huge demand for air transportation to support Iraq operations has allowed the KC-135 tanker to operate more frequently in its secondary role as a personnel and cargo transport. The KC-135 always had space for cargo or passengers, but has rarely used in this role. That changed about six years ago.
Every KC-135 can carry a combination of 40 tons of cargo or 37 passengers. In Iraq, it became common for KC-135s to move wounded troops hospitals in Germany or the United States. Previously, the C-9 was used for this, but that aircraft was retired in 2003. However, many of the other aircraft used for this, like C-130s, also have to make refueling stops to get from Iraq to the United States. A KC-135 can do it non-stop. So KC-135s coming back from a tour in Iraq or Afghanistan, will often carry patients, and a CCATT team.