continued to present problems as in earlier tests. Bombardment tests were extensive but the spotting techniques, ordnance, and communications used remained unsatisfactory. The only significant improvements for the landing forces were the new Army Radios that were highly effective for communications and the Marine pack howitzer batteries showing that they could deploy on the shore efficiently. Plus, they learned that aerial attacks had to be made at certain right angles to the direction of the attack to avoid friendly fire. The pilots however argued that they lacked the special-type of attack aircraft and the proper air-ground communications before they were to gain precision in strafing and bombing. Two aircraft squadrons, from Quantico, VA. and North Island, composed of the VF, VO, VB, and VJ aircraft. Also, FLEX 3 was the first time cargo nets used for embarking troops to the landing boats. The method proved a success, but as in the past, other Marines were loaded into boats at the rail before lowering. The origins of the destroyer-transports, or APDs were not widely known at that time until it was first mentioned in an after action report when Brigadier General James J. Meade suggested destroyers might solve the dual problem of a shortage of amphibious transports and naval gunfire support. With such ships "troops could move quickly close into shore and disembark under protection of the ships' guns." The Navy apparently agreed and decided to experiment with one of its flush-deck, four-stack destroyers. It had built a large number of these during World War I and most were now in obsolete compared to the battleships that were being used as troop transports during those times. And he further concluded that the battleships can be pressed on to other naval missions instead of being relied for troop transportation. Although the APD provided lesser carrying capacity and limited ability in carrying landing crafts and heavy equipment. Of these various naval elements of APDs, the Navy detached Battleship Division One including the , , and had added. The , which was reconfigured as a mobile aerial bombing target. The total amphibious landing force was composed of approximately 4,700 Army and Marine Corps personnel. While firing a scheduled secondary battery practice on board the USS Wyoming on the last day of the exercises at San Clemente Island, an explosion occurred in the #13 5-inch gun mount, killing one officer and six enlisted personnel. Thirteen