June 12, 2012:  South Korea has ordered 367 CBU-105 sensor fuzed weapons from the United States. Average cost is $900,000 each, including maintenance, training, and equipment, plus spare parts and training bombs. This is part of a South Korean buildup to deal with a possible North Korean invasion, or messy collapse and civil war in the north. That might include a war with China.

First used during the 2003 Iraq war, the CBU-105 Sensor Fuzed Weapon is a cluster type bomb that releases computer controlled and radar equipped BLU-108 submunitions that hunt for armored vehicles below and destroy them. Each submunition is, in effect, a little robot programmed to find and destroy vehicles below. The CBU-105 can be used to attack formations of tanks, giving most of the submunitions an opportunity to destroy a vehicle. South Korea will equip some of its T-50 jet trainers with the CBU-105. The T-50 is designed to also operate as a bomber or fighter.

CBU-105 is a half ton, GPS guided bomb carrying ten BLU-108 submunitions, each of which uses a parachute to slowly descend. The submunition radar seeks out armored vehicles. If it spots one the guidance system maneuvers the submunition towards the vehicle and fires a shaped charge that generates a self-forging warhead that is basically a bolt of molten metal travelling at high speed. This penetrates the thinner top armor of the vehicle and messes up the insides. This is similar to the Iranian shaped charge IEDs used in Iraq. If the submunition radar does not spot (via its internal computer and library of vehicle types) a tank or other armored vehicle, it attacks any vehicle within a hundred meters or so. If there are no vehicles the submunition detonates on the ground so that it does not lie around the battlefield causing a hazard. The BLU-108 is designed so that fewer than one percent of them will land and not detonate. These unexploded bomblets are a danger to anyone living or passing through the area.

The BLU-108 was developed at the end of the Cold War, to be a major weapon against the thousands of Russian tanks aimed at Western Europe. Development was not completed until the late 1990s, and the U.S. Air Force reduced its purchasing plans from several hundred thousand BLU-108s to less than 50,000.