Action off Bougainville The Action off Bougainville was a naval and air engagement on the South Pacific Theater of World War II near Bougainville , Papua New Guinea on 20 February 1942 . In the engagement , a United States Navy aircraft carrier task force on its way to raid the Imperial Japanese military base at Rabaul , New Britain was attacked by a force of land - based bomber s of the Imperial Japanese Navy . The U . S . task force was commanded by Admiral Wilson Brown and the Japanese aircraft forces were under the command of Eiji Gotō . In the ensuing engagement , the Japanese air group was almost completely annihilated , losing 15 of 17 bombers sent to attack the American carrier group . The US lost only two fighters in defense , and no ships were damaged . As a result of the loss of surprise , however , the Americans retired without raiding Rabaul as originally planned . Because of the heavy losses in bombers , the Japanese were forced to delay their planned invasion of New Guinea , giving the Allies more time to prepare defenses against the Japanese advances in the South Pacific . Prelude . Following the capture of the port of Rabaul during the battle of Rabaul , Japanese forces proceeded to turn it into a major base . Concerns grew in the allied command that with the fall of Rabaul the San Francisco - Australia sea lane supply line would be threatened and ordered the supply line to be patrolled . Admiral Chester William Nimitz and Admiral Brown devised a plan to solve the threat on the supply line by attacking the newly captured Rabaul . Task Force 11 ( TF 11 ) and ANZAC Squadron were tasked with undertaking the raid . Unfortunately , ANZAC Squadron lacked the fuel oil to head north while TF 11 sailed north to its launching point north - east of Rabaul planned for 21 February . Battle . TF 11 with , from the harbor at Rabaul , detected an unknown aircraft on radar from the ship at 10 : 15 . A six - plane combat patrol was launched , two fighters being directed to investigate the contact . These two planes , under command of Lieutenant Commander Thach shot down a four - engined Kawanishi H6K 4 " Mavis " flying boat about out at 11 : 12 . Later , two other planes of the combat patrol were sent to another radar contact ahead , shooting down a second " Mavis " at 12 : 02 . A third contact was made out , but reversed course and disappeared . Rabaul having been alerted of the presence of U . S . naval forces in the area , alerted Vice Admiral Shigeyoshi Inoue at the Imperial Japanese Fourth Fleet headquarters in Truk , who ordered an initial air strike to be conducted from Rabaul and also ordered the Cruiser Division 6 , consisting of the heavy cruisers , , , and to intercept TF 11 . Seventeen Japanese Mitsubishi G4M 1 " Betty " bombers of the 4 " Kokutai " took off from Vunakanau Aerodrome , Rabaul to attack TF 11 . Admiral Brown , having lost the element of surprise , decided to break off the attack against Rabaul and started to retire from the area . At 15 : 42 , a jagged vee signal was detected on radar , but the contact then was lost , but reappeared at 16 : 25 west . Nineteen F4F - 4 Wildcat s from " Lexington " were sent to intercept the incoming targets . Of the nine incoming " Betty " s from 2nd " Chûtai " of 4 " Kokutai " , at this time five had already been shot down . At 16 : 49 , a second formation of " Betty " s were detected by radar only out , on the disengaged side of the task force , completely unopposed , from 1st " Chûtai " of 4 " Kokutai " . " Lexington " only having two Wildcats , piloted by Lieutenant Marion Dufilho and Lieutenant Edward O ' Hare , left to confront the intruders , flew eastwards and arrived above eight " Bettys " nine miles out at 17 : 00 . Dufilho ’ s guns jammed and leaving only O ' Hare to protect the carrier from the enemy formation in V formation flying very close together . O ' Hare employing a high - side diving attack accurately placing bursts of gunfire into a " Betty " ' s right engine and wing fuel tanks ; when the stricken craft of " Nitō Hikō Heisō " Tokiharu Baba ( " 3rd Shotai " ) on the right side of the formation abruptly lurched to starboard , he ducked to the other side of the V formation and aimed at the enemy bomber of " Ittō Hikō Heisō " Bin Mori 3rd " Shotai " on the extreme left . When he made his third and fourth firing passes , the Japanese planes were close enough to the American ships for them to fire their anti - aircraft guns . The five survivors managed to drop their ordnance , but all 10 bombs missed . O ' Hare ' s hits were so concentrated , the nacelle of a " Betty " literally jumped out of its mountings , after O ' Hare blew up the leading " Shōsa " Takuzo Ito ' s " Betty " ' s port engine . O ' Hare believed he had shot down five bombers , and damage a sixth . Lieutenant Commander John Thach arrived at the scene with other pilots of the flight , later reporting that at one point he saw three of the enemy bombers falling in flames at the same time . O ' Hare had destroyed only three " Betty " s : " Nitō Hikō Heisō " , Tokiharu Baba ' s from 3rd " Shotai " ; " Ittō Hikō Heisō " , Susumu Uchiyama ' s ( flying at left wing of the leading V , 1st " Shotai " ) ; and the leader of the formation , " Shōsa " , Takuzo Ito ' s . This last ( flying on the head of leading V ) " Betty " ' s left engine was hit at the time it dropped its ordnance . Its pilot " Hikō Heisōchō " Chuzo Watanabe tried to hit " Lexington " with the damaged plane . He missed and flew into the water near " Lexington " at 17 : 12 . Another two " Bettys " were damaged by O ' Hare ' s attacks . " Ittō Hikō Heisō " Kodji Maeda ( 2nd " Shotai " , left wing of V ) safely landed at Vunakanau aerodrome and " Ittō Hikō Heisō " Bin Mori was later shot down by Lieutenant Noel Gayler when trying to escape from " Lexington " . Aftermath . As a result of the loss of surprise , Brown canceled the planned raid on Rabaul and retired from the area . Because of the high losses in bomber aircraft , the Japanese postponed their impending invasion of Lae - Salamaua , Papua New Guinea from 3 – 8 March 1942 . Two " Mavis " flying boats were also shot down which were shadowing the U . S . force , as well as two other Japanese scout aircraft lost in operational accidents while participating in the day ' s action . The U . S . lost two fighters to defensive gunfire from the bombers , but one pilot survived , while no damage was inflicted on the U . S . warships . U . S . Navy pilot Edward O ' Hare was awarded the Medal of Honor for his actions .