An average night's pattern of pre-planned fires was as follows: Combined TOTs from 9 batteries (4-6); separate battalion TOTs (Army 4-6, Marine 10-15), battery multiple volley individual missions (40-50); battery H&Is (20-30). Normal 1 gun, 1 round H&Is were not used; this type of fire was of little value. Marine and Army artillery were employed in target areas and at ranges to reduce to a minimum check fires caused by the arrival of TPQ and reconnaissance aircraft. Later, as we learned finesse, air was given the targets south of the base and west of the maximum range of the 175mm guns; 1/13 was given any targets whose range required a maximum ordinate of less than 14,000 feet (altitude of TPQ run); and the 175mm guns were assigned targets to the north, northwest, and east of the base. Such were the pre-planned fires.(155) [Illustration: A 105mm howitzer of 1/13 lashes out at NVA troops surrounding Khe Sanh. The artillery battalion was in direct support of the 26th Marines. (USMC Photo A190832)] [Illustration: The 175mm guns of the 2d Battalion, 94th Artillery, USA were in general support of the Khe Sanh garrison. This gun was located at Camp J. J. Carroll. (USMC Photo A190709)] In addition to volume, reaction time was a key factor. Unless friendly aircraft in the target area necessitated a check fire, artillery response was immediate--no matter what the weather. To test the proficiency of the Fire Direction Center and the gun crews, Colonel Lownds periodically walked into the FSCC bunker, pointed to a spot on the huge map which adorned the wall and directed Lieutenant Colonel Hennelly to hit it. The coordinates were quickly sent to the FDC where they were either fed into the FADAC computer or worked out manually and the firing data was then passed on to the gun crew. After adjusting the tube, the gunners slammed a round home and sent it on its way. The entire process usually took less than 40 seconds. This "instant artillery" constantly hampered enemy movement within the TAOR and helped break up numerous attacks.(156)