Bombing of Wewak The Bombing of Wewak was a series of air raids by the USAAF Fifth Air Force , on 17 – 21 August 1943 , against the major air base of the Imperial Japanese Army Air Force on the mainland of New Guinea , at Wewak . The four raids , over a five - day period , represented a decisive victory for the Allies : the Japanese Fourth Air Army lost about 100 planes on the ground and in the air , reducing its operational strength to about 30 planes . Ten aircraft from the U . S . Fifth Air Force were lost . Background . By August 1943 , the Fourth Air Army — which had been formed in June for the New Guinea campaign — had 130 operational aircraft . This was one third of its full complement of planes and represented an operational strength of 50 % . According to Japanese historian Hiroyuki Shindo : " . . . the major causes of this low operational rate were widespread illness among the aircrews , along with . . . the lack of aircraft replacements . " Nevertheless , the planes included state - of - the - art fighters like the formidable Nakajima Ki - 43 " Hayabusa " ( " Oscar " ) , the new in - line - engined Kawasaki Ki - 61 " Hien " ( " Tony " ) , and the twin - engined Kawasaki Ki - 45 " Toryu " ( " Nick " ) ground attack / night fighter . During the U . S . and Australian Armies ' Lae campaign , the Fourth Air Army moved a large number of aircraft out of range of Allied fighters , to a cluster of airfields near Wewak , some 400 miles ( 650 km ) west of the Huon Peninsula . Escort fighter s did not have the range to reach Wewak from existing Allied air bases , and the Allies considered large - scale , long - range raids by unescorted heavy bomber s to be at risk of heavy losses . The Allied air commander in the South West Pacific Area , Major General George Kenney , devised a plan for a major attack on Wewak . Allied personnel started construction of two dummy airfields , relatively close to Japanese infantry positions on the Huon Peninsula , north of Lae . Small construction crews created large clouds of dust , to create the impression that major construction was underway . The Japanese responded by frequently bombing the " airfields " , and apparently preventing occupation by Allied units . Simultaneously , at Tsili Tsili , away , the Allies constructed a real airfield and transferred fighter planes there before the Japanese discovered its existence . ( However , the Australian official history says the new , secret base was the separate airfield at nearby Marilinan , from Lae . ) On 12 August , the Fourth Air Army began to carry out a wave of raids on the Allied air bases at Mount Hagen , Bena Bena , Wau , Salamaua and elsewhere . Some small Allied raids were undertaken against Wewak . Attacks . On 17 August , 47 B - 24 Liberator s and B - 17 Flying Fortress es made a pre - dawn attack on the main base at Wewak and satellite airfields at Boram , Dagua and But . Japanese aircraft were parked wing - tip to wing - tip on runways . At Boram , 60 Japanese planes were being warmed up by their crews . Some attempted to take off but were destroyed in the process . At 09 : 00 , more than 30 B - 25 Mitchell s — escorted by more than 80 P - 38 Lightning s — made strafing attacks on Boram , Wewak , and Dagua . Another attack on the airfields was dispatched on the morning of 18 August to strafe and drop the fields from low altitude . The 3rd Attack Group was assigned to attack Wewak and Boram fields , while the 38th Bomb Group was sent further west to attack Dagua and But airdromes . Each of the 62 bombers was loaded with 12 clusters of three " para - frag " bombs . B - 24s of the 90th Bomb Group bombed Wewak from high altitude , while 53 B - 25s succeeded in reaching Wewak and attacked the airfields again . Only three U . S . aircraft were lost in the raids , but in one loss Major Ralph Cheli was awarded the Medal of Honor . The raids caught the Japanese unprepared . Their New Guinea airbases were inadequate in terms of the concealment of planes , in hangars and other shelters , and they relied almost completely on a visual warning system , which did not allow enough time for aircraft on the ground to take off or be taken under cover . These problems were compounded by the poor quality of runways , a shortage of maintenance staff and a lack of heavy equipment at forward bases . These problems were not restricted to Wewak . According the Australian official historian , during this period , at least 50 % of the Japanese aircraft lost were destroyed on the ground . Two additional raids were conducted on 20 and 21 August . The Fifth Air Force claimed 20 aircraft destroyed on 20 August , and 70 on the final day , ½ of them shot down in air combat by escorting P - 38s . Aftermath . Colonel Kazuo Tanikawa — an Eighth Area Army staff officer — later said : The Fourth Air Army had been reduced to an operational strength of about 30 planes , and this meant a virtual end to Japanese air operations in New Guinea until replacements arrived . The Allies could now conduct air operations virtually uncontested as far away as Aitape , whereas previously Madang had been the extent of air operations . The Fourth Air Army recovered to an extent but never again reached the strength it had in August 1943 . The last major air combat between Allied and Japanese aircraft took place on 3 June 1944 . The final aerial victories of the New Guinea campaign for the USAAF and Royal Australian Air Force occurred in June 1944 . By that time the Fourth Air Army had ceased to exist .