While observing an air strike from the Marine division sector, General Lamson-Scribner noted that prior to the strike there had been no preparatory firing on enemy antiaircraft artillery positions. After the strike he discussed this matter with General Selden, who “directed me to discuss with his chief of staff what I had observed and my suggestions that division firepower for ‘flak suppression’ be coordinated with air strikes.”[109] The upshot of this was that the division chief of staff suggested that the 11th Marines regimental commander and his staff members develop an SOP[110] for using artillery flak suppression fires in support of close air support strikes. It was believed that proper utilization of these fires would reduce aircraft losses and further increase the opportunity for a successful close air support mission by destruction of enemy antiaircraft weapons.[111] [109] MajGen Frank H. Lamson-Scribner ltr to Hd, HistBr, G-3 Div, HQMC, dtd 12 Oct 66. [110] An SOP, standing operating procedure, is a set of instructions for conducting operations that lend themselves to established procedures. _JCS, JD_, p. 133. [111] With respect to the effect of enemy fire on attack aircraft, the CO, MAG-33 later commented that “Antiaircraft artillery has a direct deterioration effect on pilot accuracy, particularly with regard to care in getting on target and doing a precise job.” CO, MAG-33 ltr to CG, 1st MAW, dtd 25 Jul 52, quoted in _PacFlt EvalRpt_ No. 5, p. 9-76. On 30 June 1952, the 11th Marines published the SOP. Since the objective was to prevent enemy fire from interfering with friendly strike planes, the key to the entire procedure was the precise coordination of artillery fire with the delivery of aircraft ordnance. As Colonel Henderson described the system: When the infantry regiment received word of an air strike, the air liaison officer plotted on the map ... the target of the strike, the orbit point, the direction of approach, and the altitude ... and direction of pullout. Then the artillery liaison officer, by looking at the map, could determine which of the Chinese positions could bring effective fire on the strike aircraft. The artillery battalion had prearranged code names and numbers for every antiaircraft position. All the artillery liaison officer had to do was pick up the phone and tell the F.D.C. [fire direction center] ‘flak suppression’ and read off what targets he wanted covered.