The Australian troops in the Markham-Ramu Valley campaign, and elsewhere in New Guinea, were supported by Allied aircrews. Many attacks on Japanese positions were preceded by 'softening up' and 'suppression' of these positions by American or Australian bombers and fighters that attacked with bombs, cannon fire and machine-guns. This helped to reduce casualties among the Australian troops.
If there was one type of aircraft that the troops were perhaps most fond of, it was the Australian-built Boomerangs that seemed to be flying over the battle areas, at low level, almost every single day. They were operated by No 4 Squadron, Royal Australian Air Force, which had first supported Allied troops around Buna in late 1942. At first the squadron had used Wirraways and, flying low level reconnaissance sorties, the pilots and observers of these aircraft proved adept at spotting Japanese positions, and guiding artillery and air attacks. They had even gained an element of fame when one of the pilots, Flying Officer John 'Jack' Archer, shot down a Zero.
In the months following this battle, 4 Squadron replaced most of its Wirraways with single-seat Boomerangs. Hastily designed and manufactured as a fighter (Australia's first locally produced fighter) by the Commonwealth Aircraft Corporation in Melbourne at the height of the invasion scare, the Boomerang had proved disappointing in its intended role. Fighter squadrons had instead been equipped with American-built Kittyhawks and British-built Spitfires as these became available. The Boomerang would have been relegated to training units but it was realised that it might make an ideal army cooperation, or tactical reconnaissance, aircraft. It was highly manoeuvrable, and able to be flown well at low level.
The Boomerangs, and the men who maintained and flew them, were based at a number of airfields during the New Guinea campaigns. They supported virtually every infantry division, even the 1st US Marine Division after it was landed on the island of New Britain at the of 1943. When operating over the forward area, Boomerangs were flown in pairs – while the bottom pilot scanned the terrain for signs of Japanese troops and positions, the top pilot scanned the skies for enemy fighters. They needed to be spotted early, as the Boomerang was no match for enemy fighters, and the only real hope of survival was to escape flying at low level. The other danger was mistaken identity – at least two aircraft were shot down by Americans in 'friendly fire' incidents.
Pilots were well trained, having each spent several months with the sister squadron, 5 Squadron RAAF, in Queensland, flying on training exercises with the Army, before being posted to New Guinea. They learned to spot the smallest of signs – footprints on riverbanks or along tracks, or perhaps broken limbs of trees, that could indicate the presence of Japanese troops. Using wireless sets, they could communicate with artillery gunners, or they could 'lead in' other Allied aircraft, by firing their tracer-equipped cannon shells into identified enemy positions, so that the attacking aircraft knew where to fire and drop their bombs.
There was a cost, with several pilots killed in action during the course of the campaigns. A few ground staff also lost their lives, as a result of accidents. Undoubtedly, the presence of these men in and over the battle area helped attain victory.