In our continuing series on RAAF operations, we take a look at the defence of Port Moresby. In 1942, Port Moresby stood between the Japanese advance and Australia’s north-eastern approaches. After the fall of Rabaul, the town came under relentless air attacks and became the centre of a desperate Allied defence. From the arrival of No. 75 Squadron’s Kittyhawks and the Battle of the Coral Sea to the fighting at Milne Bay and Kokoda, Allied air power evolved from simply holding the line to taking the war north. This is the story of the Defence of Port Moresby, 1942.
After the invasion of Rabaul on 23 January 1942 (which we covered in our previous video of this series), Port Moresby was isolated and subjected to sustained Japanese air attacks. Australian and later American air units carried the burden of its defence. Across the months that followed, thousands of sorties were flown in a campaign that would ultimately halt Japan’s southward advance and secure Australia’s north-eastern approaches.
Richard Kingsland, flying Catalinas from Port Moresby, recalls pulling out the Australian force from Rabaul after it fell to the Japanese, and then conducting night raids on Rabaul once the enemy had a foothold.
Richard Kingsland (Commanding Officer, 11 Squadron)
I moved my people out of, Rabaul was attacked and my people came down. We brought some of them out and the others were picked up by my blokes at Toll Plantation. That was a very gallant flight, finishing at dusk picking up the remnants of the Army and the air force people at Toll Plantation and flying them down to Samarai [Island] where they alighted at night.
A flight to Rabaul was a shocker getting off was extremely hard because we were overladen with fuel, we had taken off all of our armour plate out of our aircraft. We had taken the self-sealing elements out of our tanks and our wings. So we could decent load on and take it a decent way. So we would eventually get off, but you wouldn’t take off over the hills and fly to Rabaul direct, you flew down the coast because you were climbing slowly all of the way turn the corner at Milne Bay port and Samarai [Island] and then head north. You’re into the dark by then, see this is three o’clock in the afternoon, you’re into the dark and then you fly until about midnight when you get to Rabaul. Through the inter-tropic front, absolute shocker, and then waiting there everything very silent, going over Rabaul and getting, put vulgarly, the shit shot out of you, it was really just, you were just sitting ducks up there, and then hopefully turning around and coming home to Moresby or Samarai,
March 1942 – First Response
Following the rapid Japanese advance to Lae and Salamaua early March, Allied forces responded with a carrier strike on the 10th of March, launching aircraft over the Owen Stanley Range to attack Japanese shipping. The raid sank and damaged multiple vessels, but it did not remove the growing threat.
At Port Moresby, the situation was critical. With minimal defences in place, No. 75 Squadron was rushed north with barely days of preparation. Arriving on the 21st of March, its Kittyhawks were immediately committed to combat, intercepting Japanese reconnaissance aircraft within hours.
Based in Port Moresby, 11 Squadron Commander Richard Kingsland was losing aircraft in battle and in accidents and needed fighter cover. They were coming; however, the first new fighters to arrive at Moresby encountered an unexpected welcome…
Richard Kingsland (Commanding Officer, 11 Squadron)
…we had no fighter protection whatsoever, except for forty-four days when they sent number 75 Squadron up to Moresby. They gathered, things were crook, we were getting bombed every day and I was losing aircraft, and they scrounged from the Americans a set of Kittyhawk fighters assembled them at Townsville, brought crews in from down south, not really fighter boys, gave them a weeks training and they flew up to Port Moresby. Port Moresby attacked, this is how bad the intell was, attacked the anti-aircraft gunners with light machine guns attacked and damaged four of the aircraft coming in, one irreparably. None were fortunately shot right down. Then they fought for forty-five days, got whittled away.
Throughout March, 75 Squadron operated under constant pressure. It defended Port Moresby against repeated bombing raids while also striking forward Japanese bases. A notable attack on Lae highlighted both the aggression and vulnerability of these early operations—aircraft were lost, but damage was inflicted on the ground.
By late March, No. 75 Squadron was flying daily sorties, often outnumbered and sustaining losses, while keeping Port Moresby operational. Their actions, together with anti-aircraft defences, prevented the Japanese from neutralising the airfield during a critical phase of the campaign.
Allied reinforcements began arriving by the end of the month. The US 8th Bombardment Squadron (flying Douglas A-24 dive bombers) reached Port Moresby on the 31st of March 1942, and six Bell P-39 Airacobra fighters of the 36th Pursuit Squadron joined later in May.
April 1942 – Attrition and Reinforcement
As April began, Japanese raids intensified, often involving large formations of bombers escorted by fighters. Lewis, a wireless operator and gunner on Catalinas, explains the situation when landing in Port Moresby bay.
BERNARD “LEWIS” HARTE
Wireless Operator/Gunner — No. 20 Squadron RAAF
When we got back to Port Moresby we would stay on the plane overnight and disperse into a little bay in Port Moresby harbour. This is when the Japs came in because they would come in and bomb Port Moresby at night. Rather than be sitting ducks, we would go up into a little inlet there and stay there, sleep there the night. Apart from that, we couldn’t get accommodation. It was only a small RAAF base and to sleep you would have to sleep under someone else’s bed, which wasn’t very accommodating. The only trouble there was the mosquitoes were very bad there and we had to take a lot of Atebrin.
No. 75 Squadron continued to suffer heavy losses. Experienced pilots were killed or captured, and aircraft numbers dwindled. Despite this, the defence held. Japanese bombing caused disruption and damage but failed to eliminate Port Moresby as an operational base.
Richard “Dick” Cresswell CO No. 77 Squadron RAAF
75 Squadron initially had a hard time in Moresby. Lost eighteen pilots, in five weeks, then at Milne Bay both squadrons lost pilots. But they saved the day. Caused the Japanese not to do a retreat, but to change their objective. They pulled out of Milne Bay.
By the end of April, additional American fighter squadrons (the US 35th and 36th) had arrived, allowing the exhausted RAAF unit to be withdrawn by early May. No.75 had claimed 39 enemy aircraft destroyed (54 more damaged) and had lost 24 of its Kittyhawks and 12 pilots. The defence had come at a cost, but it had bought time.
May 4-8 1942 – Battle of The Coral Sea
In early May, the campaign shifted decisively to the sea. Japanese forces moved to seize Port Moresby by amphibious assault, supported by carrier groups. Allied intelligence detected the plan (Operation MO), and carrier forces moved to intercept.
Between the 4th and 8th of May, aircraft from opposing carriers fought a series of engagements across the Coral Sea. U.S. carriers, supported by Australian cruisers, blocked the Japanese carrier force. Air attacks from USS Lexington and Yorktown sank the Japanese light carrier Shōhō on the 7th of May and, on the 8th, badly damaged the fleet carrier Shōkaku. In return, Japanese dive-bombers fatally damaged USS Lexington (it was abandoned and scuttled on 11 May); USS Yorktown was damaged but survived.
Although losses were significant on both sides, the outcome was strategically decisive. The Japanese invasion force was turned back. For the first time, Port Moresby had been saved not by local defence but by a wider operational victory.
May–June 1942 – Continued Air Pressure
Despite the outcome at Coral Sea, Port Moresby remained under threat from land-based Japanese aircraft operating from Rabaul and northern New Guinea. Raids continued through May and June, including some of the heaviest attacks yet.
Shipping in the harbour was targeted, and losses were incurred despite fighter opposition. Allied air units, now reinforced with American fighters, fought back but still faced numerical and operational challenges.
An important part of Allied defence was early warning of incoming enemy aircraft, provided by outlying observers. Francis, a wireless operator, describes how he decoded such messages.
Francis Lynch, RAAF Wireless & Cipher Operator
If you got a signal and you started to decode it and it said the first word was “tiger,” you had to call the intelligence officer straight away because that was from our representatives from behind Jap lines in enemy territory. So that was his prefix, tiger. He might say, “30 Betties [Betty bombers],” they were Japanese bombers, “Escorted by 20 Zekes [Zero fighters].” “Leaving Rabaul 0900 hours to attack.” How he knew all this, I don’t know. But we called the intelligence officer and all that. So they were called Coastwatchers quite a number of them. The one in Rabaul, how he would get information like that, because the Japs would have planned it in their operation room. So they must have had an English-speaking native or something in the vicinity who pretended he couldn’t speak, or Japanese I mean, who couldn’t speak. Because no way could a white man be so close to know that. Even we, in Port Moresby, even though we only had a couple of airstrips, we never knew what planes were going to attack when, even though we were right there on the spot. Not unless you happened to go out the aerodrome and someone would say there, “They’re going off again to hit Lae.” So how those Coastwatchers knew used to always be a mystery to me.
By late June, however, the scale of Japanese attacks began to decline. Losses at Coral Sea, combined with shifting priorities, reduced the intensity of operations. At the same time, Allied infrastructure improved, and additional airfields expanded the defensive network.
By mid-1942, Port Moresby had weathered its most vulnerable period.
Mid–Late 1942 – From Defence to Campaign
With a seaborne invasion no longer viable, Japanese strategy shifted. Instead of attacking Port Moresby directly, forces landed on the northern coast of New Guinea and began advancing overland across the Owen Stanley Range—while also planning a supporting move against Milne Bay to the east.
On the 21st of July 1942, Japanese troops landed at Buna and Gona, initially unopposed, and quickly secured their beachheads. Reinforcements followed, laying the groundwork for an advance along the Kokoda Trail. Allied air power responded almost immediately. Bombers based at Port Moresby struck landing areas and supply ships, disrupting the buildup and inflicting early losses.
This marked a fundamental shift in the air war.
BERNARD “LEWIS” HARTE
Wireless Operator/Gunner — No. 20 Squadron RAAF
I was doing work over in New Guinea in the flying boat as a crewmember at a place called Buna. At Buna we observed the Japanese making their first landing on New Guinea soil. They went up to Gona, which is a Catholic mission there and they raped a lot of missionary ladies and nuns and so forth. We actually saw them coming ashore. We didn’t drop any bombs; we just reported them. That was the first landing that I can recall on New Guinea soil and it was Buna Bay. Later on we went back and we bombed them.
Aircraft were now supporting a broader campaign across extremely difficult terrain. Fighters continued with interception duties, while bombers increasingly targeted supply lines, airfields, and staging areas. Reconnaissance became critical for tracking enemy movement through the jungle and mountains.
Transport aircraft proved decisive. They delivered supplies, evacuated the wounded, and sustained forces in areas where ground transport was impossible. Air power became essential not only for combat but also for survival.
At the same time, the Japanese attempted to outflank Allied positions by landing at Milne Bay in late August, aiming to capture its airfields. This time, they met immediate resistance. Allied aircraft, operating from prepared forward strips, attacked landing craft, supply barges and troop concentrations from the outset. A continuous air attack disrupted the Japanese advance before it could gain momentum.
William Dutton tells us about the effectiveness of the air defence at Milne Bay at the time.
William Dutton, Ground Crew, 75 Squadron RAAF
A coast watcher at the northern entrance of Ward Hunt Strait, he sighted two Japanese landing, 50 foot landing barges, filled with Japanese troops moving down the coast towards Milne Bay. That was on the 24th of August and then on the 25th of August in response to a coast watcher on Goodenough Island. Goodenough Island’s not far from Milne Bay, it’s about 20 minutes’ flying in a Kittyhawk I suppose. In response to the coast watcher at Goodenough Island, he sighted these two barges putting ashore at Goodenough Island, well two flights of Kittyhawks, one led by Squadron Leader Johnny Piper and the other by Flying Officer Adam, they moved in for the kill. One flight acted as top cover while the other went in at ground level and strafed the barges. Well after about, I think they made about four passes on the barges, they not only set all the barges on fire and killed a few of the Japanese but, unbeknown to the pilots, they’d taken out all of the Japanese radio equipment.
So the next day the Kittyhawks took off and they put two 50 pound bombs where the belly tanks go underneath the aircraft. And they attacked the convoy but without success and you’ve got to appreciate here that the Kittyhawk’s a fighter squadron, they’ve got no bombsights and dropping a bomb from where the belly tank is it’s just hit and miss. And then just after that the Hudsons and the other Kittyhawks they attacked the squadron, the invasion fleet and they had a near miss on the transport but they hit one of these submarines, chasers or whatever it was, minesweeper. And that didn’t go into Milne Bay.
Aircraft repeatedly struck landing forces, supply movements, and troop concentrations. Japanese attempts to build momentum were disrupted before they could mature into sustained operations.
By early September, the Japanese had withdrawn. The battle at Milne Bay (which we’ve covered in a previous video) marked the first major land defeat for Japanese forces in the Pacific and demonstrated the growing effectiveness of Allied air power when integrated with ground operations.
September–October 1942 – Turning the Tide
As the Kokoda campaign progressed, Japanese forces reached their closest point to Port Moresby, only 30 km away on the Kokoda Track, but their advance was slowing.
Supply lines stretching across the mountains became increasingly vulnerable. The terrain made close air support extraordinarily difficult. Aircraft had to cross the Owen Stanley Range before descending into narrow valleys and jungle, where Japanese positions could be almost impossible to see.
Harold Rowell, a Boston pilot with No. 22 Squadron, describes hugging the jungle terrain in his aircraft over the Owen Stanley Range.
Harold Rowell, Boston Bomber pilot, 22 Squadron RAAF.
We much preferred when the troops were fighting on the top of the ridges, and we had an open go, but when they were on the bottom of the valley floor in the twisting river bed, [it was] hard to get down there but harder to get out. Particularly if the river went more than a hair-pin bend. The gunners complained that the trees were coming through the back hatch so it was time to go a little higher. If you got too far at the bottom and spent too much time there sometimes it was touch and go whether you had enough speed to climb out again.
By late September, the Japanese advance stalled. Allied forces began moving north, and air operations shifted to offensive interdiction. Lionel describes the Boston Bombers of No. 22 Squadron going on the offensive.
Lionel Hambly, Wireless Air Gunner, No. 22 Squadron RAAF
When we came over the Owen Stanleys we could come down and hug the ridge relatively close to the ground, the hills and valleys. You would then come to where your target was which was generally on the coast, Gona, Salamaua, Lae. And then he would pick out the spot we were going to aim at and the pilot just aimed the plane at the target and we would drop one bomb at a time…if it was not a heavily defended one, otherwise he would drop the four and strafe as he approached it and then go out to sea and come home. If it was heavily defended he would keep going around strafing until there were no bullets left and then come home. There was not a lot to see.
It was all low level stuff, and depends. If they were dropping the bombs then they might be about a hundred feet up. But with strafing the closer you got to the ground the better the chance of hitting something, targets and people. You stayed as close as you could to the tree tops, as you climbed up the valley and mountain and came back over the Owen Stanley which was 14,000 feet I think. Quite a climb. But it was uneventful. You couldn’t see much and you just hoped there was no damage to the plane.
October–December 1942 – Toward Offensive Operations
By the final months of 1942, the role of Allied air power was changing. The aircraft defending Port Moresby were increasingly being used to support the advance on the ground.
Harold Rowell, Boston Bomber pilot, 22 Squadron RAAF.
Our task in New Guinea was basically army close support. The army had a tough nut to crack or the Japanese were being particularly stubborn. They would ring up and say please will you come and soften them up. And we would say when, how and when and we would slip over and. One of our advantages was they didn’t know if we were going to bomb them or strafe them. It was all dive bombing and strafing. And you don’t know if you are going to get 1500 pound of bombs or eight machine guns at you. You tend to duck your head and we went over. On the way back on debriefing, I didn’t know how or where anything happened. They said, “Where did your bombs go?” I said “No idea”.
The objective was now the destruction of Japanese forces before they could regroup. Aircraft numbers increased, and operations grew more coordinated and aggressive.
Bombers targeted supply centres and airfields, while fighters expanded their role in offensive operations. Air attacks supported ground offensives around Buna and Gona, weakening Japanese positions ahead of assaults.
Airfields at Port Moresby became busier and more developed, reflecting the shift from improvised defence to sustained offensive capability.
By December, the strategic balance had clearly shifted.
Conclusion
Over the course of 1942, the air war over New Guinea changed fundamentally.
What began as a defence of Port Moresby became a campaign in which aircraft could range beyond the mountains, find the enemy, disrupt his supply lines and support Allied forces advancing north.
The aircraft, crews and bases that had once been fighting simply to hold the line were now becoming the means by which that line was pushed forward.
By the end of the year, Port Moresby was no longer simply a defensive outpost. It had become a key base for the Allied campaign into Japanese-held territory.
