The early base was modest: two earth runways, a hangar, a control tower, accommodation blocks, and a squadron of CAC Wirraways, Australian-built fighters that were already obsolete by world standards. Then the strategic picture darkened. By late 1941 the United States, worried about supplying its forces in the Philippines, secretly arranged for space at Townsville to develop ferrying facilities for heavy bombers. American officers arrived in October, and the gravel strips were torn up and rebuilt as three sealed runways in six weeks of round-the-clock work. The job was finished on 15 December 1941. Japan had entered the war a week before. The timing was almost absurdly tight, and from that moment Garbutt was a frontline installation.

Through 1942 the field outgrew itself again and again. American Airacobras and Warhawks replaced the outclassed Wirraways. The base became North-Eastern Area Headquarters and home to the headquarters of the US Fifth Air Force's bomber command. Reconnaissance and bomber crews flew from here across the whole theatre, from New Guinea to the Solomons, and aircraft based at Townsville took part in the Battle of the Coral Sea, fought just a few hundred kilometres out to sea in May 1942. A sprawling depot grew up to assemble and repair American aircraft, its hangars and taxiways spilling across what are now whole suburbs of Townsville. So many airfields sprouted nearby that the original base had to be renamed Garbutt, after the local railway siding, just to keep them straight.

For three nights in late July 1942 the war came directly to Garbutt. Long-range Japanese flying boats from Rabaul attacked Townsville after dark, probably as a diversion timed to coincide with landings on the New Guinea coast. The raids were small and did little harm. On one night a stick of bombs fell on the Town Common more than four kilometres from the nearest buildings. The heavy anti-aircraft battery on Mount St John opened fire, and on the second and third nights P-39 Airacobras scrambled from Garbutt to chase the raiders down; on 29 July a fighter damaged a departing bomber. Perhaps because of that spirited defence, the Japanese never came back. Those three ineffectual nights were the only time enemy bombs fell on the city.

As the fighting moved north, Townsville's role shifted from defence to industry. The depots became vast rear-echelon workshops, overhauling engines, repacking parachutes, and modifying bombers, including converting scores of B-25s into low-level strafers, each conversion costing hundreds of man-hours. When the war ended in 1945 the buildings were auctioned off and the base shrank back toward its 1940 footprint. But it never closed. Garbutt flew maritime patrols in the postwar decades, weathered cyclones that destroyed hangars and aircraft, and grew again as Australia shifted its defences northward and the army built nearby Lavarack Barracks into its largest base. Today RAAF Base Townsville is an active installation supporting army aviation, regional operations, and disaster relief, with a heritage centre on site that reopened in 2025. The runways laid down in a six-week panic in 1941 are flying still.