The island commander’s air defense capabilities also grew substantially. Cactus Air Force, organized into a fighter command and a strike (bomber) command, now operated from a newly redesignated Marine Corps Air Base. The Henderson Field complex included a new airstrip, Fighter Two, which replaced Fighter One, which had severe drainage problems. Brigadier General Louis Woods, who had taken over as senior aviator when Geiger returned to Espiritu Santo, was relieved on 26 December by Brigadier General Francis P. Mulcahy, Commanding General, 2d Marine Aircraft Wing. New fighter and bomber squadrons from both the 1st and 2d Wings sent their flight echelons forward on a regular basis. The Army added three fighter squadrons and a medium bomber squadron of B-26s. The Royal New Zealand Air Force flew in a reconnaissance squadron of Lockheed Hudsons. And the U.S. Navy sent forward a squadron of Consolidated PBY Catalina patrol planes which had a much needed night-flying capability.
The aerial buildup forced the Japanese to curtail all air attacks and made daylight naval reinforcement attempts an event of the past. The nighttime visits of the Tokyo Express destroyers now brought only supplies encased in metal drums which were rolled over the ships’ sides in hope they would float into shore. The men ashore desperately needed everything that could be sent, even by this method, but most of the drums never reached the beaches.
Still, however desperate the enemy situation was becoming, he was prepared to fight. General Hyakutake continued to plan the seizure of the airfield. General Hitoshi Immamura, commander of the _Eighth Area Army_, arrived in Rabaul on 2 December with orders to continue the offensive. He had 50,000 men to add to the embattled Japanese troops on Guadalcanal.
Before these new enemy units could be employed, the Americans were prepared to move out from the perimeter in their own offensive. Conscious that the Mt. Austen area was a continuing threat to his inland flank in any drive to the west, Patch committed the Americal’s 132d Infantry to the task of clearing the mountain’s wooded slopes on 17 December. The Army regiment succeeded in isolating the major Japanese force in the area by early January. The 1st Battalion, 2d Marines, took up hill positions to the southeast of the 132d to increase flank protection.