Yokosuka D4Y The D4Y Navy Carrier Dive bomber was operated by the Imperial Japanese Navy . Its Allied reporting name was " Judy " . The D4Y was one of the fastest dive - bombers of the war and only the delays in its development hindered its service while its predecessor , the slower fixed - gear Aichi D3A remained in service much longer than intended . Despite limited use , the speed and the range of the D4Y was nevertheless valuable , and the type was used with success as reconnaissance aircraft as well as for " kamikaze " missions . Design and development . Development of the aircraft began in 1938 at the Yokosuka Naval Air Technical Arsenal as a carrier - based dive bomber to replace the Aichi D3A . The aircraft was a single - engine , all - metal low - wing monoplane , with a wide - track retractable undercarriage and wing - mounted dive brakes . It had a crew of two : a pilot and a navigator / radio - operator / gunner , seated under a long , glazed canopy which provided good all - round visibility . The pilot of bomber versions was provided with a telescopic bombsight . The aircraft was powered by an Aichi Atsuta liquid - cooled inverted V - 12 in - line engine , a licenced copy of the German DB 601 , rated at 895 kW ( 1 , 200 hp ) . The radiator was behind and below the three - blade propeller , as in the P - 40 Warhawk . It had a slim fuselage that enabled it to reach high speeds in horizontal flight and in dives , while it had excellent maneuverability despite high wing loading , with the " Suisei " having superior performance to contemporary dive bombers such as the SB2C Helldiver . In order to conform with the Japanese Navy ' s requirement for long range , weight was minimized through not fitting the D4Y with self - sealing fuel tank s or armour . In consequence , the D4Y was extremely vulnerable and tended to catch fire when hit . Bombs were fitted under the wings and in an internal fuselage bomb bay . It usually carried one 500 kg ( 1 , 100 lb ) bomb , but there were reports that the D4Y sometimes carried two 250 kg ( 550 lb ) bombs , for example during the attack on the light aircraft carrier . Only 30 kg ( 70 lb ) bombs were carried externally . The aircraft was armed with two 7 . 7 mm ( . 303 in ) machine gun s in the nose , and one 7 . 92 mm ( . 312 inm ) Type 1 machine gun selected for its high rate of fire in the rear of the cockpit . Later , the rear gun was replaced by a 13 mm ( . 51 in ) Type 2 machine gun . This armament was typical for Japanese carrier - based bombers . The forward machine guns were retained in the " kamikaze " version . The first D4Y1 prototype made its maiden flight in December 1940 . After the prototype ' s successful trials , problems with flutter were encountered , a fatal flaw for an airframe subject to the stresses of dive bombing . Until this could be resolved , early production aircraft were used as reconnaissance aircraft , as the D4Y1 - C , which took advantage of its high speed and long range , while not over - stressing the airframe . Production of the D4Y1 - C continued in small numbers until March 1943 , when the increasing losses incurred by the D3A resulted in production switching to the D4Y1 dive - bomber , the aircraft ' s structural problems finally being solved . Although the D4Y could operate successfully from the large fleet carriers that formed the core of the Combined Fleet at the start of the war , it had problems operating from the smaller and slower carriers such as the " Hiyō " class which formed a large proportion of Japan ' s carrier fleet after the losses sustained during the Battle of Midway . Catapult equipment was therefore fitted , giving rise to the D4Y1 " Kai " ( or improved ) model . These early versions of the D4Y were difficult to keep operational because the Atsuta engines were unreliable and difficult to maintain in front - line service . From the beginning , some had argued that the D4Y should be powered by an air - cooled radial engine which Japanese engineers and maintenance crew had experience with , and trusted . The aircraft was therefore re - engined with the reliable Mitsubishi MK8P " Kinsei " 62 , a 14 - cylinder two - row radial engine . This version was designated the Yokosuka D4Y3 Model 33 . Although the new engine improved ceiling and rate of climb ( over 10 , 000 m / 32 , 800 ft , and climb to 3 , 000 m / 9 , 800 ft in 4 . 5 minutes , instead of 9 , 400 m / 30 , 800 ft and 5 minutes ) , the higher fuel consumption resulted in reduced range and cruising speed , while the bulky engine obstructed the forward and downward view of the pilot , hampering carrier operations . These problems were tolerated because of the increased availability of the new variant . The last version was the D4Y4 Special Strike Bomber . This one - seat " kamikaze " aircraft , capable of carrying one 800 kg ( 1 , 760 lb ) bomb , was put into production in February 1945 . It was equipped with three RATO boosters for terminal dive acceleration . This aircraft was an almost ideal " kamikaze " model : it had a combination of speed ( 560 km / h / 350 mph ) , range ( 2 , 500 km / 1 , 550 mi ) and payload ( 800 kg / 1 , 760 lb ) probably not matched by any other Japanese aircraft . The D4Y5 Model 54 was a planned version designed in 1945 . It was to be powered by the Nakajima NK9C " Homare " 12 radial engine rated at 1 , 361 kW ( 1 , 825 hp ) , would have a new four - blade metal propeller of the constant - speed type , and would have more armour protection for the crew and fuel tanks . Ultimately , 2 , 038 of all variants were produced , mostly by Aichi . Operational history . Lacking armor and self - sealing fuel tanks , the " Suiseis " did not fare well against Allied fighter s . They did , however , cause considerable damage to ships , including the carrier , which was nearly sunk by a single D4Y . The D4Y was operated from the following Japanese aircraft carriers : , , , , , , , , , and . The D4Y1 - C reconnaissance aircraft entered service in mid - 1942 , when two of these aircraft were deployed aboard " Sōryū " at the Battle of Midway , where both were lost when " Sōryū " was sunk . Marianas . During the Battle of the Marianas , the D4Ys were engaged by U . S . Navy fighters and shot down in large numbers . The D4Y was faster than the Grumman F4F Wildcat , but not the new Grumman F6F Hellcat . The Japanese aircraft were adequate for 1943 , but the rapid advances in American materiel in 1944 ( among them , the introduction in large numbers of the " Essex " - class aircraft carrier ) left the Japanese behind . Another disadvantage suffered by the Japanese was their inexperienced pilots . The U . S . Task Force 58 struck the Philippine airfields and destroyed the land air forces first , before engaging the Japanese naval aircraft . The result was what the Americans called " The Great Marianas Turkey Shoot " , with 400 Japanese aircraft shot down in a single day . A single Hellcat pilot , Lieutenant Alexander Vraciu , shot down six D4Ys within a few minutes . One D4Y was said to have damaged Leyte and Philippines . The D4Y was relegated to land operations where both the liquid - cooled engine D4Y2 , and the radial engine D4Y3 fought against the U . S . fleet , scoring some successes . An unseen D4Y bombed and sank the " Princeton " on 24 October 1944 . D4Ys hit other carriers as well , by both conventional attacks and " kamikaze " actions . In the Philippines air battles , the Japanese used " kamikazes " for the first time , and they scored heavily . D4Ys from 761 " Kokutai " may have hit the escort carrier on 25 October 1944 , and the next day , . Both were badly damaged , especially " Suwannee " , with heavy casualties and many aircraft destroyed . A month later on 25 November , , , and were hit by " kamikazes " , almost exclusively A6M Zero fighters and D4Ys , with much more damage . D4Ys also made conventional attacks . All these D4Ys were from 601 and 653 " Kokutai " . In defence of the homeland . Task Force 58 approached southern Japan in March 1945 to strike military objectives in support of the invasion of Okinawa . The Japanese responded with massive " kamikaze " attacks , codenamed " Kikusui " , in which many D4Ys were used . A dedicated Kamikaze version of the D4Y3 , the D4Y4 with a non - detachable 800 kg bomb attached in a semi - recessed manner , was developed . The Japanese had begun installing rocket boosters on some Kamikazes , including the D4Y4 in order to increase speed near the target . As the D4Y4 was virtually identical in the air to the D4Y3 it is difficult to determine the sorties of each type . Carriers and were damaged by D4Ys of 701 Wing on 18 March . On 19 March , the carrier Franklin was hit with two bombs from a single D4Y , which then escaped despite heavy anti - aircraft fire . " Franklin " was so heavily damaged that she was retired until the end of the war . Another D4Y hit the carrier . On 12 April 1945 , another D4Y , part of " Kikusui " mission N . 2 , struck " Enterprise " , causing some damage . During " Kikusui " N . 6 , on 11 May 1945 , was hit and put out of action by two " kamikazes " that some sources identify as D4Ys . This was the third " Essex " - class carrier forced to retire to the States to repair . Night fighter . The D4Y was faster than the A6M Zero and some were employed as D4Y2 - S night fighter s against Boeing B - 29 Superfortress bombers late in the war . The night fighter conversions were made at the 11th Naval Aviation Arsenal at Hiro . Each D4Y2 - S had bomb equipment removed and a 20 mm Type 99 cannon with its barrel slanted up and forwards ( similar to the German " Schräge Musik " armament fitment ) installed in the rear cockpit . Additionally some examples also carried two or four 10 cm air - to - air rockets under the wings . However , the lack of radar for night interceptions , inadequate climb rate and the B - 29 ' s high ceiling limited the D4Y2 - S effectiveness as a night fighter . Little is known of their operations . Last action . At the end of the war D4Ys were still being used operationally against the U . S . Navy , and among the last of these were 11 aircraft led by Vice Admiral Matome Ugaki on a search mission on 15 August 1945 , of which all but three were lost . Survivors . A surviving restored D4Y1 ( serial 4316 ) is located at the Yasukuni Jinja Yūshūkan shrine in Tokyo . A second example , an engineless D4Y1 ( serial 7483 ) was recovered from Babo Airfield , Indonesia in 1991 and as of 2012 has been restored / rebuilt by the Planes of Fame Air Museum in Chino , California to non - flying ( but taxiable ) condition as a D4Y3 . The installed radial engine is American and as a result the cowling profile is not quite accurate . Numerous photos of the rolled out aircraft have now been published . Said aircraft as of the spring of 2012 , is still in natural metal . However , as a Hinomaru has been painted on the fuselage , it is presumed that the D4Y1 " Judy " will be finished in the standard IJN paint scheme . ISBN 978 - 8 - 38945 - 012 - 8 .