The controlling agency at Khe Sanh for these strikes was Air Support Radar Team-Bravo (ASRT-B), Marine Air Support Squadron 3 which had moved from Chu Lai on 16 January. The ground controllers operated from a heavily reinforced van which housed their sensitive computer equipment and used the TPQ-10 radar to guide aircraft to their target; thus, the missions were called TPQs.[55](147) The radar emitted a pencil-shaped beam which detected and locked on to the aircraft. Using target coordinates provided by the FSCC, the controller programmed the enemy position, ballistic characteristics of the bombs, current winds, and other pertinent data into a computer which was connected to the radar. The computer also received inputs from the radar and, in turn, provided corrections in airspeed, altitude, and heading which the operator passed on to the pilot. The controller closely monitored his set and, at a predetermined release point, called a "Mark" to the pilot who "pickled" his bombs.[56] In specially-equipped aircraft, such as the A-4 Skyhawk and the A-6 Intruder, the bombs could be released automatically from the ground. One ground controller could handle a single plane, a section (two planes), or a division (four planes) on the same pass as long as the pilots flew in a tight formation and the radar did not break lock. One of the controllers' favorite aircraft was the A-6 because it packed such a heavy wallop; a single Intruder usually carried 28 500-pounders. Any fighter/bomber, however, could be used as long as it carried low-drag ordnance and the pilot could make a smooth run.(148)