The U.S. prefers to keep quiet about where its electronic surveillance and warfare aircraft are operating but the news gets out one way or another, especially with all those cell phone cameras out there. For example in early March 2015 one such aircraft was reported to have crashed in northern Iraq, apparently the victim of equipment malfunction. The four crew survived and were quickly picked up. The wreckage was surrounded by special operations troops as key parts of the aircraft were removed and the rest blown up. Photos of the aircraft got out and the tail number was tracked and confirmed as one the air force MC-12Ws that had been transferred to the army. There is another MC-12W known to be operating in Niger against Boko Haram Islamic terrorists in Nigeria. These aircraft can detect, monitor and jam all forms of wireless communications in an area. Since Islamic terrorists tend to lack any sophisticated military-grade communications gear an MC-12W overhead is very bad news.
The MC-12W is basically a militarized version of the commercial Beech King Air. The army began using this Beech aircraft as the RC-12 in the 1970s, and was seeking a replacement when the U.S. Air Force realized that the RC-12 was suitable for use as a Predator substitute (to do surveillance and intel collection). The first air force MC-12Ws entered service over Iraq and Afghanistan. In a few years the air force had acquired over forty MC-12Ws. Since 2014 the U.S. Army and SOCOM have been taking over RC-12Ws and adding more electronics and new software turned that them into army EMARSS (Enhanced Medium Altitude Reconnaissance and Surveillance System) aircraft. In effect these were the RC-12 replacements the army had long been seeking for so long.
MC-12W pilots require a nine week training course, which includes simulator time, and twelve flights in the actual aircraft. The two equipment operators can do all their training on a simulator. The MC-12 itself is a modified version of the earlier RC-12 electronic reconnaissance aircraft.
The first MC-12 squadron was deployed to Iraq where, in six months, the dozen aircraft flew over a thousand sorties. That's about four sorties per week per aircraft. After 2011 most MC-12s were sent to Afghanistan, and found the experience (and success) there similar to that in Iraq.
The MC-12W provides the same service as a UAV (full motion video) in addition to electronic monitoring (radio, cell phone, etc.). The air force converted some existing King Air 350s, as well as buying new ones, to obtain nearly fifty MC-12s for duty as, in effect, a Predator UAV replacement.
The King Air 350 is a 5.6 ton, twin engine aircraft. The MC-12 can stay in the air for up to eight hours per sortie. Not quite what the Predator can do (over 20 hours per sortie), but good enough to help meet the demand. The MC-12 has advantages over UAVs. It can carry over a ton of sensors, several times what a Predator can haul. The MC-12 can fly higher (11 kilometers/35,000 feet) and is faster (over 500 kilometers an hour, versus 215 for the Predator.) The MC-12s cost about $20 million each, more than twice what a fully equipped Predator goes for. The MC-12's crew consists of two pilots and two equipment operators. Some of the sensors are operated from the ground. The King Air 350 (and earlier models) has long been used by the army and air force as a light cargo and passenger transport. That model was called the C-12 Huron and that was soon adapted to intelligence and electronic warfare use as the RC-12.