The experiment was an immediate success. The Division set up a photo laboratory near the VMO-6 CP for rapid processing and printing. A helicopter stood by for rapid delivery to the units concerned.[215] [215] _Ibid._ Not all the variations in tactics were innovations. Lieutenant Colonel Bernard T. Kelly, commanding officer of 3/7, revived an old device on 31 May by using indirect automatic weapons fire with good effect. Four water-cooled heavy machine guns provided long range (2,600 yards) plunging fires on the reverse slopes of hills in support of his leading elements during the final attack on Yanggu.[216] [216] Col B. T. Kelly, interv of 9 Jun 58. _MAG-12 Moves to K-46 at Hoengsong_ Delay and uncertainty were still the two great stumbling blocks to adequate air support for the ground forces under the JOC control system. Marine officers contended that infantry units sometimes took unnecessary casualties as a consequence. Worse yet, there were occasions when the expected planes did not arrive at all. Statistics kept by the 1st MAW and Navy during the spring of 1951 upheld these conclusions. During the Inchon-Seoul operation, the average delay in receiving air support had been 15 minutes as compared to 80 minutes in May and June of 1951. Approximately 35 minutes of this time was required to process the request through JOC. And only 65 to 70 percent of the sorties requested were ever received by Marine ground forces.[217] [217] _PacFlt Interim Rpt_ No. 2, II, 523–537. Generals Shepherd and Harris had discussed the problem during the early spring of 1951 with General Partridge of the Fifth Air Force. Several compromises were reached, and for brief periods the 1st Marine Division received more air support than it could use. Unfortunately, these periods were at times of the least need. When the chips were down, the old delays and uncertainties reappeared. General Partridge commented: The 1st Marine Air Wing was assigned for operational control by the Fifth Air Force and it was used just as any of the other units of the Fifth were employed, that is, in support anywhere along the battle front were it appeared to be most urgently needed. In every action such as took place in Korea when the resources and especially the air resources are far too few, ground commanders inevitably feel that they are being shortchanged. They are trying to accomplish their objectives under the most difficult circumstances and with the minimum number of casualties and they want all the assistance from the air that they can get. I am sure I would feel the same in similar circumstances. However, there was never enough air support to satisfy everyone and I was most unhappy that this was the case.