crater. Guidance This system depends upon the accurate positioning of the aircraft by either a fixed ground radar or on-board navigation equipment. The ground radar controller, or aircrew navigator if applicable, is responsible for positioning the aircraft prior to final countdown and release. Primary aircrew considerations include accurate ballistic and wind computations provided by the navigator, and precision instrument flying with strict adherence to controller instructions. Due to its extremely powerful blast effects, the minimum safe altitude for releasing this weapon is above ground level (AGL). Operations The BLU-82 was originally designed to clear helicopter landing zones and artillery emplacements in Vietnam. The first use of a BLU-82 occurred on 22 March 1970, when one was dropped north of Long Tieng, Laos during Campaign 139. During Operation Lam Son 719 in 1971 25 BLU-82 bombs were dropped on NVA and Pathet Lao forces in Laos. They were dropped by U.S. C-130 aircraft not only to clear landing zones, but also to strike against specific targets such as warehouses, vehicle parks, and enemy troop concentrations. South Vietnamese VNAF aircraft dropped BLU-82 bombs on NVA positions in desperation to support ARVN troops in the Battle of Xuân Lộc in the last days of the Vietnam War. During the Mayaguez incident, a Lockheed MC-130 dropped one BLU-82 to assist U.S. Marine forces attempting to extract themselves from Koh Tang island. Eleven BLU-82Bs were palletized and dropped in five night missions during the 1991 Gulf War, all from Special Operations MC-130 Combat Talons. The initial drop tested the ability of the bomb to clear or breach mine fields; however, no reliable assessments of mine clearing effectiveness are publicly available. Later, bombs were dropped as much for their psychological effect as for their anti-personnel effects. Due to the size of the conventional blast, a British SAS unit that witnessed the explosion mistakenly assumed the U.S. had used a nuclear weapon and radioed back to their headquarters exclaiming, "Sir, the blokes have just nuked Kuwait!". The U.S. Air Force dropped several BLU-82s during the campaign to destroy Taliban and al-Qaeda bases in Afghanistan to attack and demoralize personnel and to destroy cave complexes. American forces began using the bomb in November 2001 and again a month later during the Battle of Tora Bora. On 15 July 2008, airmen from the Duke Field 711th Special Operations Squadron, 919th Special Operations Wing dropped the last operational BLU-82 at