Mitsubishi G4M

The Mitsubishi G4M (long designation: Mitsubishi Navy Type 1 attack bomber: 一式陸上攻撃機, 一式陸攻 Ichishiki rikujō kōgeki ki, Ichishikirikkō) was the main twin-engine, land-based bomber used by the Imperial Japanese Navy Air Service in World War II. The Allies gave the G4M the reporting name Betty. Japanese Navy pilots called it Hamaki (葉巻, "cigar", lit. "leaf roll") due to its cylindrical shape.

The G4M had very good performance, especially in operational range; this was achieved by its structural lightness and an almost total lack of protection for the crew, with no armor plating or self-sealing fuel tanks. These omissions proved to be the aircraft's weakness when confronted with American fighter aircraft during the Pacific War.[1]

A Mitsubishi G4M1; with a non-standard roundel - a white square instead of the white circle surrounding the hinomaru.
Role Medium bomber
Manufacturer Mitsubishi
Designer Kiro Honjo
First flight 23 October 1939
Introduction June 1941
Retired 1945
Primary user Imperial Japanese Navy Air Service
Number built 2,435

Design and development

The G4M was designed for a long range and high speed at the time of its introduction. Consequently, several weight-saving measures were incorporated into the design, such as dispensing with self-sealing fuel tanks and armor, which caused Allied fighter pilots to give it derisive nicknames such as "the one-shot lighter", "the flying Zippo" and "the flying cigar" because of their tendency to explode or catch on fire from any slight damage to the wing fuel tanks after being hit by aerial machine gun fire or ground-based anti-aircraft fire. Similarly, pilots of the Imperial Japanese Navy despairingly called the G4M the "type one lighter", the "flying lighter" and the "hamaki" ("cigar"). This was partially due to the fact that on many occasions, the G4M was used for low-altitude torpedo attacks on ships during which their performance advantages were negated. The G4M was frequently shot down by anti-aircraft artillery fire, and even by small arms. The G4M's relatively large size made it an easy gunnery target, and the predictable approach path required for a torpedo run made for a generally easy interception by Allied fighter aircraft.

Mitsubishi G4M captured on ground 1945.jpeg
A Mitsubishi G4M2 on the ground.

When used for medium- to high-altitude bombing against stationary land targets like supply depots, seaports or airfields, it was much harder to intercept. Using its long range and high speed, the G4M could appear from any direction, and then it could be gone before any fighters intercepted them. The 20 mm cannon in its tail turret was much heavier armament than was commonly carried by bombers of either side, making aerial attacks from the rear quite dangerous for the Allied fighter aircraft. Sometimes, assuming they did not catch fire after being hit in the wings by flak from the ground or by machine gun bullets from enemy fighters, G4Ms also proved to be able to remain airborne despite being badly damaged. For example, after the attack of the 751 Kōkūtai (air group) on the USS Chicago during the Battle of Rennell Island, three out of four surviving aircraft (of the original eleven) returned despite flying with only one engine.


  • G4M1 Model 11: 1172 examples (including prototypes)
  • G4M2 models 22, 22 Ko and 22 Otsu: 429 examples
  • G4M2a, models 24, 24 Ko, 24 Otsu, 24 Hei, and 24 Tei: 713 examples
  • G4M3 models 34 Ko, 34 Otsu, and 34 Hei: 91 examples
  • G6M1: 30 examples
  • Total production of all versions: 2,435 examples

Operational history

Ohka carried under the belly of a Betty of 721st Naval Air Group
721st Kōkūtai G4M2e bomber carrying an Ohka (image of a plastic model)

The G4M was similar in performance and missions to other contemporary twin-engine bombers such as the German Heinkel He 111 and the American North American B-25 Mitchell. These were all commonly used in anti-ship roles. The G4M Model 11 was prominent in attacks on Allied shipping from 1941 to early 1944, but after that it became increasingly easy prey for Allied fighters.

The G4M was first used in combat on 13 September 1940 in Mainland China, when 27 "Bettys" and Mitsubishi C5Ms of 1st Rengo Kōkūtai (a mixed force including elements of the Kanoya and Kizarazu Kōkūtai) departed from Taipei, Omura, and Jeju City to attack Hankow. The bombers and the reconnaissance aircraft were escorted by 13 A6M Zeros of 12th Kōkūtai led by the IJN lieutenant, Saburo Shindo. A similar operation occurred in May 1941. In December 1941, 107 G4Ms based on Formosa of 1st Kōkūtai and Kanoya Kōkūtai belonging to the 21st Koku Sentai (air flotilla) crossed the Luzon Strait en route to bombing the Philippines; this was the beginning of Japanese invasions in the Southwest Pacific Theater.

Mitsubishi G4M1 bombers attack the invasion force between Guadalcanal and Tulagi on 8 August 1942 (80-G-17066)
IJN aviators pressed home a torpedo attack against American ships off Guadalcanal on 8 August 1942, suffering heavy losses. The plane on the left and at extreme low-level (approximately five meters) was flown by Jun Takahashi, who was still alive in 2016.

The G4M's most notable use as a torpedo bomber was in the sinking of Prince of Wales and Repulse off the eastern coast of Malaya on 10 December 1941. The G4Ms attacked along with older Mitsubishi G3M "Nell" bombers, which made high-level bombing runs. Prince of Wales and Repulse were the first two capital ships to be sunk exclusively by air attacks during a war, while in open waters. The bomber crews were from the Kanoya Air Group of Kanoya Kōkūtai (751 Ku), Genzan Air Group of Genzan Kōkūtai (753 Ku), and the Mihoro Air Group of Mihoro Kōkūtai (701 Ku), trained in torpedo attacks at an altitude of less than 10 metres (30 ft), and in long-range over-ocean navigation, so they could attack naval targets moving quickly at sea. Nine G4Ms participated in the long range bombing raid of Katherine, Northern Territory, on 22 March 1942 (the deepest inland attack on Australian territory during the war at over 200 miles from the coast). G4Ms later made many attacks against Allied ships and also land targets during the six-month-long Guadalcanal Campaign (in the Solomon Islands) in late 1942.

On 8 August 1942, during the second day of the U.S. Marine landings on Guadalcanal, 23 IJNAF torpedo-carrying G4M1s attacked American ships at Lunga Point. 18 of the G4M1s were shot down, by very heavy anti-aircraft fire and carrier-based F4F fighters. In all 18 Japanese crews – approximately 120 aviators – were lost at the beginning of August 1942. More than 100 G4M1s and their pilots and crews were lost (with no replacements or substitutes available) during the many battles over and near Guadalcanal (August to October 1942).[2] In the two days of the Battle of Rennell Island, 29 and 30 January 1943, 10 out of 43 G4M1s were shot down during night torpedo attacks, all by U.S. Navy anti-aircraft fire. About 70 Japanese aviators, including Lieutenant Commander Higai, were killed during that battle.

Crashed Mitsubishi G4M floating off Tulagi on 8 August 1942 (80-G-K-383)
Crashed G4M1 floating at Tulagi 8 August 1942

Probably the best-known incident involving a G4M during the war was the attack resulting in the death of Admiral Yamamoto. On 18 April 1943, sixteen P-38 Lightnings of the 339th Fighter Squadron of the 347th Fighter Group, Thirteenth Air Force, shot down a G4M1 of the 705th Kokutai with the tailcode "T1-323", carrying Admiral Yamamoto.

Yamamoto's airplane crash
Yamamoto's G4M1 in the aftermath of the attack.

The G4M Model 11 was replaced by the Models 22, 22a/b, 24a/b, 25, 26, and 27 from June 1943 onward, giving service in New Guinea, the Solomons, and the South Pacific area, in defense of the Marianas and finally in Okinawa. Other G4Ms received field modifications, resulting in the Model 24j. This model carried the Yokosuka MXY7 Ohka Model 11 suicide flying bomb, beginning on 21 March 1945, with disastrous results due to heavy Allied fighter opposition.

After the loss of Okinawa, G4Ms constituted the main weapon of the land-based Japanese naval bomber force. It consisted of 20 Kōkūtai at the end of the war. This included the testing air group, which was equipped in 1944–45 with the latest version G4M3 Models 34 and 36, though these arrived too late to affect the course of the war.

From November 1944 to January 1945, G4Ms were one of the main types of aircraft used in the Japanese air attacks on the Mariana Islands, and plans to use converted G4Ms to land commandos on the islands were developed in mid-1945 and cancelled only at the end of the war.

As part of the negotiations for the surrender of Japan, two demilitarized G4Ms, given the call-signs Bataan 1 and Bataan 2, flew to Ie Shima, carrying the first surrender delegations on the first leg of their flight to Manila. The G4Ms were painted white with green crosses, and were escorted by American P-38 fighters.[3]

The G4M's intended successor was the Yokosuka P1Y Ginga, although because of production problems, the changeover was only begun by the time the war ended.



G4M1 prototypes
(Mitsubishi Navy Type 1 attack bomber) / (Mitsubishi Navy Experimental 12-Shi land attacker). Two prototypes built.
G4M1 Model 11
(Mitsubishi Navy Type 1 Attack Bomber Model 11). The first bomber model of series, with 1,140 kW (1,530 hp) Mitsubishi MK4A "Kasei" Model 11 engines driving three-blade propellers. The following modifications were made during production:
  • March 1942: the first aircraft (241st production example) fitted with Mitsubishi MK4E "Kasei" Model 15 engines with larger superchargers for better high altitude performance, became standard in August 1942 from 406th aircraft onwards. These MK4E-engined aircraft have often (erroneously) been referred as the "G4M1 Model 12".
  • Summer 1942: propeller spinners introduced
  • March 1943: from 663rd machine onwards, 30 mm (1.181 in) rubber ply sheets installed beneath the wing outer surfaces to protect the underside of the fuel tanks (speed reduced by 9 km/h (4.9 kn; 5.6 mph) and range by 315 km (170 nmi; 196 mi), 5 mm (0.197 in) armour plates added into tail gunner's compartment.
  • Spring 1943: outer half of the tail cone cut away in order to improve tail gunner's field of fire.
  • August 1943: a completely redesigned tail cone, with reduced framing and wide V-shaped cut out; this form of tail cone was also used in all G4M2 models.
  • September 1943: individual exhaust stacks from 954th airframe onwards

Production of the G4M1 ended in January 1944.


The first of the four G4M2 prototypes flew in December 1942 (Mitsubishi Navy Type 1 Attack Bomber Model 22). It differed from the preceding model in having Mitsubishi MK4P "Kasei" Model 21 engines with VDM electric four-blade propellers capable of full feathering function, redesigned main wings with LB type laminar flow airfoil.[N 1] and widened tail horizontal stabilizer wing area, which improved service ceiling to 8,950 m (29,360 ft) and maximum speed to 437 km/h (236 kn; 272 mph). Main wing fuel tanks were enlarged to 6,490 l (1,710 US gal; 1,430 imp gal) which increased the range to 6,000 km (3,200 nmi; 3,700 mi) (overloaded, one way). An electrically powered dorsal turret featuring a 20 mm (0.787 in) Type 99 cannon was introduced in place of G4M1's dorsal position with a 7.7 mm (0.303 in) Type 92 machine gun, total guns armed were two 20 mm (0.787 in) Type 99 cannons (one tail turret, one top turret), and four 7.7 mm (0.303 in) Type 92 machine guns (one nose, two waist, and one cockpit side). External differences also included increased nose glazing, flush side gun positions instead of blisters, and rounded tips of wings and tail surfaces. These major improvements also made it possible for the G4M2 to carry more powerful bombs; one 1,055 kg (2,326 lb) Navy Type 91 Kai-7 aerial torpedo or one 800 kg (1,800 lb) bomb or two 500 kg (1,100 lb) bombs or one 800 kg (1,800 lb) Type 3 No. 31 bomb (ray-detective type bomb) and twelve 60 kg (130 lb) bombs. The G4M2 entered service in mid-1943.

G4M Type 1 Attack Bomber Betty launching Baka G4M-10
G4M2e Model 24 Tei launching a suicide Yokosuka MXY-7 Ohka "Baka" (wind tunnel model experiment)
Betty bomber Darwin (AWM P02822-001)
Betty bombers during an air raid over Darwin, Australia.
G4M2 Model 22
(Mitsubishi Navy Type 1 Attack Bomber Model 22) the base model, the first production example completed in July 1943. Introduced bulged bomb bay doors from 65th aircraft onwards, and an optically flat panel in the nose cone from the 105th aircraft onwards.
G4M2 Model 22Ko
(Mitsubishi Navy Type 1 Attack Bomber Model 22 Ko) very similar to previous model. Carried Type 3 Ku Mark 6 search radar and was armed with 20 mm (0.787 in) Type 99 Model 1 cannon s replacing the 7.7 mm (0.303 in) Type 92 machine guns in the lateral positions.
G4M2 Model 22 Otsu
(Mitsubishi Navy Type 1 Attack Bomber Model 22 Otsu) dorsal turret cannon changed to longer-barreled 20 mm (0.787 in) Type 99 Model 2 cannon.
G4M2a Model 24
(Mitsubishi Navy Type 1 Attack Bomber Model 24) modified Model 22, Mitsubishi MK4T Kasei 25 1,340 kW (1,800 hp) engines, with bulged bomb bay doors as standard for larger bomb capacity. Externally distinguishable from the Model 22 by a carburetor air intake on the top of the engine cowling.
G4M2a Model 24 Ko
(Mitsubishi Navy Type 1 Attack Bomber Model 24 Ko) armament similar to Model 22 Ko.
G4M2a Model 24 Otsu
(Mitsubishi Navy Type 1 Attack Bomber Model 24 Otsu) armament similar to Model 22 Otsu.
G4M2a Model 24 Hei
(Mitsubishi Navy Type 1 Attack Bomber Model 24 Hei) modified 24 Otsu, with one 13.2 mm (0.520 in) Type 2 machine gun mounted in tip of the nose cone, radar antenna relocated from that position to above the nose cone.
G4M2b Model 25
(Mitsubishi Navy Type 1 Attack Bomber Model 25) one G4M2a modified to Mitsubishi MK4T-B Kasei 25 Otsu 1,360 kW (1,820 hp) engines. Only experimental.
G4M2c Model 26
(Mitsubishi Navy Type 1 Attack Bomber Model 26) two G4M2as modified to Mitsubishi MK4T-B Ru Kasei 25b 1,360 kW (1,820 hp) engines with turbochargers.
G4M2d Model 27
(Mitsubishi Navy Type 1 Attack Bomber Model 27) one G4M2 modified to Mitsubishi MK4V Kasei 27 1,340 kW (1,800 hp) engines.
G4M2e Model 24 Tei
(Mitsubishi Navy Type 1 Attack Bomber Model 24 Tei) special version for the transport of the ramming attack bomb plane Kugisho/Yokosuka MXY-7 Ohka ("Baka") Model 11, conversions of G4M2a Model 24 Otsu and 24 Hei. Had armour protection for the pilots and fuselage fuel tanks.
MXY11 (Yokosuka Navy Type 1 attack bomber ground decoy)
ground decoy non-flying replica of Mitsubishi G4M2 developed by Yokosuka


Mid- or late-production G4M1 Model 11s with the propeller spinners and rubber ply beneath the wing fuel tanks.
Early production G4M1s of Kanoya Kōkūtai with the original shape tail cones.
G4M in USAAF markings
A captured G4M2
G4M3 Model 34
(Mitsubishi Navy Type 1 Attack Bomber Model 34 Tei) redesigned G4M2 with added self-sealing fuel tanks, improved armor protection and an entirely new tail gunner's compartment similar to that of late model B-26 Marauders. Wings were also redesigned and the horizontal tailplane was given dihedral. Armed with two 7.7 mm (0.303 in) Type 92 machine guns in nose cabin and in both side positions, and one 20 mm (0.787 in) Type 99 Model 1 cannon in dorsal turret and tail. Entered production in October 1944 in G4M3a Model 34 Ko form with 20 mm (0.787 in) Type 99 cannon in side positions instead of machine guns.
G4M3a Model 34 Hei
(Mitsubishi Navy Type 1 Attack Bomber Model 34 Hei) similar modifications as in corresponding Model 24 variants.
G4M3a Model 34 Otsu
(Mitsubishi Navy Type 1 Attack Bomber Model 34 Otsu) similar modifications as in corresponding Model 24 variants.
G4M3 Model 36
(Mitsubishi Navy Type 1 Attack Bomber Model 36) prototype. Two G4M2 Model 34 modified to Mitsubishi MK4-T Kasei 25b Ru 1,360 kW (1,820 hp) engines.


(Mitsubishi Navy Type 1 wingtip convoy fighter) initial model of the series, armed with three 20 mm (0.787 in) Type 99 cannon (two in a belly blister, one in the tail) and one 7.7 mm (0.303 in) Type 92 machine gun in the nose; 30 built.
(Mitsubishi Navy Type 1 large land trainer) trainers converted from G6M1s.
(Mitsubishi Navy Type 1 transport) G6M1s modified as transports.




 People's Republic of China
 United Kingdom
 United States

Surviving aircraft

No flyable Mitsubishi G4Ms are left although several wrecks remain scattered in southeast Asia and on Pacific islands.[7]

  • G4M1 Model 11 (Serial #1280): On display in a diorama at the Planes of Fame Air Museum in Chino, California in an unrestored condition. The only complete G4M Betty bomber.[8][9] Built in Nagoya Works No. 3 on 16 April 1942, tail number 370, which had probably crash landed before mid-1944, and was recovered from Babo Airfield, Indonesia, in 1991.[10]
  • G4M1 Betty Model 11 (Serial #1800): Assigned to the 701st Naval Air Group. Abandoned on Ballale Airfield. During August 2018, it was recovered from Ballale Island in the Solomon Islands, along with another G4M1 (Serial #2806) and the fuselage of an early model G4M1 by a "foreign salvager."[11]
  • G4M1 Betty Model 11 (Serial #2806): Tail code U-321, was assigned to the Misawa Naval Air Group in the Solomon Islands from Ballale Airfield. Was abandoned on a revetment, next to a bomb crater, both engines missing. During August 2018 it was recovered by a "foreign salvager" along with another G4M1 Betty Model 11 (Serial #1800) and a fuselage of an early model G4M1.[12]

Several other locations display pieces of G4Ms including the restored fuselage of a G4M2 is on display at the Kawaguchiko Motor Museum in Yamanashi Prefecture, Japan.[13]

Specifications (G4M1, Model 11)

Mitsubishi G4M
Mitsubishi G4M3 Betty

Data from Airreview's Japanese Navy Aircraft in the Pacific War[14], Japanese Aircraft of the Pacific War[15]

General characteristics

  • Crew: 7 (pilot, co-pilot, navigator/bombardier/nose gunner, captain/top turret gunner, radio operator/waist gunner, engine mechanic/waist gunner, tail gunner)
  • Length: 19.97 m (65 ft 6 in)
  • Wingspan: 24.89 m (81 ft 8 in)
  • Height: 4.9 m (16 ft 1 in) in rigging position
  • Wing area: 78.125 m2 (840.93 sq ft)
  • Airfoil: root: MAC118 mod (12.5%) ; tip:MAC118 mod (10%)[16]
  • Empty weight: 6,741 kg (14,861 lb)
  • Gross weight: 9,500 kg (20,944 lb)
  • Max takeoff weight: 12,860 kg (28,351 lb)
  • Powerplant: 2 × Mitsubishi MK4A Kasei 11 14-cylinder air-cooled radial piston engines, 1,140 kW (1,530 hp) each for take-off
1,050 kW (1,410 hp) at 2,000 m (6,562 ft)
1,000 kW (1,340 hp) at 4,000 m (13,123 ft)


  • Maximum speed: 428 km/h (266 mph; 231 kn) at 4,200 m (13,780 ft)
  • Cruise speed: 315 km/h (196 mph; 170 kn) at 3,000 m (9,843 ft)
  • Stall speed: 120 km/h (75 mph; 65 kn)
  • Range: 2,852 km (1,772 mi; 1,540 nmi)
  • Ferry range: 5,040 km (3,132 mi; 2,721 nmi) [N 2]
  • Rate of climb: 9.166 m/s (1,804.3 ft/min)


See also

Mitsubishi G4M in surrender markings
Bataan 1 or Bataan 2 on Ie Shima, 19 August 1945

Related development

Aircraft of comparable role, configuration and era

Related lists



  1. ^ LB type laminar airfoil was designed by Professor Tani of Tokyo University in 1937.
  2. ^ Serial no. 603 and later had 30 mm (1.2 in) thick natural rubber plates covering the outside bottoms of the wing fuel tanks but this decreased their service range by 10%.


  1. ^ Wheeler 1992, p. 64.
  2. ^ Fumio 1958, p. ?.
  3. ^ Gallagher, James P (2004). Meatballs and Dead Birds: A Photo Gallery of Destroyed Japanese Aircraft in World War II. USA: Stackpole Books. p. 154. ISBN 9780811731614.
  4. ^ Francillon 1969, p. 62.
  5. ^ "TAIC-SWPA No Number Mitsubishi G4M2 Betty (Captured USAAF Mitsubishi G4M "Betty")." J-aircraft. Retrieved 17 October 2010.
  6. ^ Francillon 1969, p. 63.
  7. ^ "Mitsubishi Type 1 Attack Bomber / G4M (Betty)". Retrieved 18 February 2019.
  8. ^ "Robert Greinert interview with Pacific Wrecks". Pacific Wrecks.
  9. ^ Taylan, Justin. "G4M1 Model 11 Betty Manufacture Number 1280 Tail 370, −321." Pacific Wrecks, 23 July 2011. Retrieved 1 January 2012.
  10. ^ Rocke, Robert. "G4M1 Betty Wreckage at Babo Airfield." Pacific Wrecks, 5 January 2011. Retrieved 1 January 2012.
  11. ^ "G4M1 Model 11 Betty Manufacture Number 1800 Tail U2-???". Pacific Wrecks.
  12. ^ "Pacific Wrecks - G4M1 Model 11 Betty Manufacture Number 2806 Tail U-321". Pacific Wrecks.
  13. ^ G4M2 Model 12 Betty Manufacture Number 12017 Tail 62-22 Pacific Wrecks Retrieved 19 August 2016
  14. ^ Aoki 1972, pp. 128–136.
  15. ^ Francillon, René J. (1979). Japanese Aircraft of the Pacific War. London: Putnam & Company Limited. pp. 378–387. ISBN 0 370 30251 6.
  16. ^ Lednicer, David. "The Incomplete Guide to Airfoil Usage". Retrieved 16 April 2019.


  • Aoki, Hideo. "Kugisho Suicide Attacker "Oka" (MXY7) Baka." Airreview's Japanese Navy Aircraft in the Pacific War. Tokyo: Kantosha Co. Ltd., 1972.
  • Aoki, Hideo. "Mitsubishi Type 1 Attack Bomber (G4M) Betty." Airreview's Japanese Navy Aircraft In The Pacific War. Tokyo: Kantosha Co. Ltd., 1972.
  • Bridgwater, H.C. and Peter Scott. Combat Colours Number 4: Pearl Harbor and Beyond, December 1941 to May 1942. Luton, Bedfordshire, UK: Guideline Publications, 2001. ISBN 0-9539040-6-7.
  • Chant, Chris. Aircraft Of World War Two. London: Grange Books PLC., 2001. ISBN 1-84084-329-2.
  • Ferkl, Martin. Mitsubishi G4M Betty (in English). Praha, Czech Republic: Revi Publications, 2002. ISBN 80-85957-09-4.
  • Francillon, PhD., René J. Imperial Japanese Navy Bombers of World War Two. Windsor, Berkshire, UK: Hylton Lacy Publishers Ltd., 1969. ISBN 0-85064-022-9.
  • Francillon, PhD., René J. Japanese Aircraft of the Pacific War. London: Putnam & Company Ltd., 1979. ISBN 0-370-30251-6.
  • Francillon, PhD., René J. Mitsubishi G4M "Betty" & Okha Bomb (Aircraft in Profile 210). Windsor, Berkshire, UK: Profile Publications Ltd., 1971.
  • Fumio, Iwaya. Chuko (Medium Attack Bomber). Tokyo: Hara Shobo, 1958.
  • Green, William. Famous Bombers of the Second World War. London: Macdonald and Jane's Publishers Ltd., 1975 (Second edition of 1959 book, reprinted at least twice: 1976 and 1977). ISBN 0-356-08333-0.
  • Gunston, Bill. The Illustrated Encyclopedia of Combat Aircraft of World War II. London: Salamander Books Ltd., (Third impression ) 1979. ISBN 0-89673-000-X.
  • Horodyski, Joseph M. "British Gamble In Asian Waters". Military Heritage. Volume 3, No. 3, December 2001, pp. 68–77. (sinking of the British battleship Prince of Wales and battlecruiser Repulse by Japanese on 10 December 1941 upon U.S. entry into World War II).
  • Morgan, Eric B. "Mitsubishi G4M Betty." Twentyfirst Profile, Vol. 2, No. 17. New Milton, Hantfordshire, UK: 21st Profile Ltd., ISSN 0961-8120.
  • Nowicki, Jacek. Mitsubishi G4M "Betty" (in Polish). Warszawa, Poland: Wydawnictwo Militaria, 1998. ISBN 83-7219-020-8.
  • Tagaya, Osamu. Mitsubishi Type 1 Rikko Betty Units of World War 2. London: Osprey Publishing, 2001. ISBN 1-84176-082-X.
  • Thorpe, Donald W. Japanese Naval Air Force Camouflage and Markings World War II. Fallbrook, California: Aero Publishers Inc., 1977. ISBN 0-8168-6587-6 (pbk.), ISBN 0-8168-6583-3 (hc.).
  • Wheeler, Barry C. The Hamlyn Guide to Military Aircraft Markings. London: Chancellor Press, 1992. ISBN 1-85152-582-3.

External links

Media related to Mitsubishi G4M at Wikimedia Commons

4th Air Group

The 4th Air Group (第四航空隊, Dai Yon Kōkūtai) was a land-based bomber aircraft unit of the Imperial Japanese Navy Air Service (IJNAS) during the Pacific campaign of World War II. The unit was formed on 10 February 1942 and flew the Mitsubishi G4M Rikko Navy Type 1 Attack Bomber aircraft. That same month, the 4th Naval Air Group (NAG) deployed to Rabaul, New Britain and supported Japanese operations during the early stages of the New Guinea Campaign, first as part of the 24th Air Flotilla and from April as part of the 25th Air Flotilla. The newly arrived unit took heavy losses on 20 February during an action off Bougainville, losing 15 of 17 bombers sent to attack a United States Navy aircraft carrier task force.

Reconstituted with replacement aircraft, the 4th NAG participated in the Battle of the Coral Sea on 7 May 1942, losing five bombers destroyed in an attack on an Australian/US warship task group. In August 1942, the unit conducted bombing raids against Allied forces newly landed on Guadalcanal. Taking heavy losses over Guadalcanal, the unit was withdrawn from the front in September 1942. On 1 November 1942 the unit was redesignated as the 702 Air Group.

Attack on Clark Field

The attack on Clark Field was part of a series of morning airstrikes on United States Pacific island military bases opening Japanese participation in World War II. The attack was intended to minimize interference from the Far East Air Force (FEAF) during the subsequent invasion of the Philippines by the Empire of Japan. Capture of the Philippines was essential to control shipping routes between Japan and the Greater East Asia Co-Prosperity Sphere. Hostilities were initiated by the attack on Pearl Harbor at 07:48 Hawaiian Time (UTC-10) on 7 December 1941. As dawn moved westward across the Pacific (and the International Date Line), daylight airstrikes followed at mid-day (UTC+12) on Wake Island, at 09:27 (UTC+10) on Guam, at 06:00 (UTC+8) on Davao, at 09:30 (UTC+8) on Baguio and at 12:35 (UTC+8) on Clark Field. United States Army Air Forces aircraft losses on the ground in the Philippines were similar to those sustained on Oahu despite nine hours available for preparations following the Pearl Harbor attack; but commanding general Douglas MacArthur avoided the disgrace suffered by Hawaiian commanding general Walter Short.

Edward O'Hare

Lieutenant Commander Edward Henry "Butch" O'Hare (March 13, 1914 – November 26, 1943) was an American naval aviator of the United States Navy, who on February 20, 1942, became the Navy's first flying ace when he single-handedly attacked a formation of nine heavy bombers approaching his aircraft carrier. Even though he had a limited amount of ammunition, he managed to shoot down five enemy bombers. On April 21, 1942, he became the first naval recipient of the Medal of Honor in World War II.

O'Hare's final action took place on the night of November 26, 1943, while he was leading the U.S. Navy's first-ever nighttime fighter attack launched from an aircraft carrier. During this encounter with a group of Japanese torpedo bombers, O'Hare's Grumman F6F Hellcat was shot down; his aircraft was never found. In 1945, the U.S. Navy destroyer USS O'Hare (DD-889) was named in his honor.

A few years later, Colonel Robert R. McCormick, publisher of the Chicago Tribune, suggested that the name of Chicago's Orchard Depot Airport be changed as a tribute to Butch O'Hare. On September 19, 1949, the Chicago, Illinois airport was renamed O'Hare International Airport to honor O'Hare's bravery. The airport displays a Grumman F4F-3 museum aircraft replicating the one flown by Butch O'Hare during his Medal of Honor flight. The Grumman F4F-3 Wildcat on display was recovered virtually intact from the bottom of Lake Michigan, where it sank after a training accident in 1943 when it went off the training aircraft carrier USS Wolverine (IX-64). In 2001, the Air Classics Museum remodeled the aircraft to replicate the F4F-3 Wildcat that O'Hare flew on his Medal of Honor flight. The restored Wildcat is exhibited in the west end of Terminal 2 behind the security checkpoint to honor O'Hare International Airport's namesake.


Funryu (奮龍, Funryū) was a series of surface-to-air anti-aircraft missiles developed in Japan at the end of the Second World War. During the missile's development in the late stages of the war, it was plagued by organisational problems and was cancelled before becoming operational.

In 1945, it was created and tested a few samples SAM Funryu, but in connection with the surrender of the Japanese Empire's work had not been completed. All the developments on the complex were destroyed after the end of hostilities.The first was the Funryu 1 and the design was an air-to-surface missile (ASM) whose specific role was anti-shipping. Funryu 1 was much like a miniature airplane. The warhead contained 8821b of explosive and guidance was via radio control. Testing of the Funryu 1 was conducted with the missile being dropped from a modified Mitsubishi G4M bomber. However, it was seen that the means to effectively control the missile in flight would require a significant amount of time to perfect and with the increase in US bombing raids against Japan, it was decided that efforts should be directed towards sur – face-to-air missiles (SAMs). Thus, the Funryu 1 was shelved and was to be the only ASM of the Funryu family.Two more advanced versions were called the Funryu 2 and the Funryu 4. The Funryu 2 was solid-fueled, 7.9 feet long, had a diameter of 12 inches and weighed about 815 pounds. The Funryu 4 was liquid-fueled, 13.1 feet long, had a diameter of 24 inches and weighed about 4,190 pounds.Funryu4, which strongly resembled the Mitsubishi J8M (with swept wings and elevons) would be guided primarily under radio control from the ground. The operator would fly the Primary version of missile Funryu2 into the vicinity of the bombers, then cut the engine and let it glide. Funryu4 was high-speed designs that could be flown directly at their target along the line of sight, easy enough to do even from the ground.

As the power plant decided to use the KR-20 rocket engine thrust to 1500 kgf with a fuel reserve of 5 minutes of work. The same engine to be used on the rocket fighter J8M1. Since the thrust of the engine is less than the starting weight of the rocket, the launch was supposed to carry out a 45 ° angle to the horizon, and climb to a great extent had to be due to aerodynamic forces.The control system has radio command to the original single-channel transmission system commands. Basic pulse signal frequency was 1000 Hz, with a division into groups. After every 200 pulses there is a brief pause. The combination of these five groups according to the duration of pulses and 200 was set commands: up, down, right, left, and explosion. Target tracking and missile intended to carry out visually, by optical means, as well as radar. The team at undermining the projectile was issued automatically when the radar signal reflected from the target coincides with the signal reflected from the SAM. Such a control system, in general, coincide with some modern systems.In accordance with this project in the arsenal of Nagasaki was made a prototype "Funryu 4" rockets bench tests which began (and then ended) August 16, 1945, that is already the day after the end of hostilities.Shortly thereafter, the soldiers with dynamite destroyed all equipment associated with the program "Funryu" so that did not get anything in the hands of the Americans, it would be associated with these missiles.

Kawanishi Baika

The Kawanishi Baika (梅花, "Ume Blossom") was a pulsejet-powered kamikaze ("divine wind") aircraft under development for the Imperial Japanese Navy towards the end of World War II. The war ended before any were built.

Kiro Honjo

Kiro Honjo (本庄 季郎, Honjō Kirō) (1901–1990) was a Japanese aircraft designer who worked for Mitsubishi and designed aircraft used in World War II such as the Mitsubishi G3M (Nell) and the Mitsubishi G4M (Betty).He was portrayed in the 2013 Japanese animated movie The Wind Rises as a colleague of the designer of the Zero fighter, Jiro Horikoshi.

List of aircraft of the Imperial Japanese Navy

The following is the List of aircraft of the Imperial Japanese Navy Air Service and the Japan Maritime Self-Defense Force, both past and present.

Maloelap Atoll

The Maloelap Atoll (Marshallese: M̧aļoeļap, [mˠɑɫʌ͡ɔɔ̯-ɛ̯ɛ͡ʌɫɑ͡æpʲ]) (also spelled Maleolap) is a coral atoll of 71 islands in the Pacific Ocean, and forms a legislative district of the Ratak Chain of the Marshall Islands. Its land area is only 9.8 square kilometres (3.8 sq mi), but that encloses a lagoon of 972 square kilometres (375 sq mi). It is located 18 kilometres (11 mi) north of the atoll of Aur. In 2011 the population of the islands of the atoll was 682.

The largest of the islands that make up the atoll are Taroa (the administrative center of the atoll), in the northeast, and Kaben in the northwest. Only three of the other islands in the atoll are inhabited: Airuk, Wolot and Jang. The island is served by Air Marshall Islands via Maloelap Airport.

Medium bomber

A medium bomber is a military bomber aircraft designed to operate with medium-sized bombloads over medium range distances; the name serves to distinguish this type from larger heavy bombers and smaller light bombers. Mediums generally carried about two tons of bombs, compared to light bombers that carried one ton, and heavies that carried four or more.

The term was used prior to and during World War II, based on available parameters of engine and aeronautical technology for bomber aircraft designs at that time. After the war, medium bombers were replaced in world air forces by more advanced and capable aircraft.

Mitsubishi G1M

The Mitsubishi G1M was a long-range twin-engined Attack Bomber built by Mitsubishi for the Imperial Japanese Navy in the 1930s.

Mitsubishi G3M

The Mitsubishi G3M (Kyūroku-shiki rikujō kōgeki-ki (九六式陸上攻撃機): Type 96 land-based attack aircraft "Rikko"; Allied reporting name "Nell") was a Japanese bomber and transport aircraft used by the Imperial Japanese Navy Air Service (IJNAS) during World War II.

Mitsubishi Kasei

The Mitsubishi Kasei (火星, Mars) was a two-row, 14-cylinder air-cooled radial engine built by Mitsubishi Heavy Industries and used in a variety of World War II Japanese aircraft, such as Mitsubishi J2M and Mitsubishi G4M. The Mitsubishi model designation for this engine was A10 while it was an experimental project, in service it was known as the MK4, and known as the Ha101 & Ha111 by the Army and Kasei by the Navy. According to unified designation code it was Ha-32 of the variants from 11 to 27.

Parasite aircraft

A parasite aircraft is a component of a composite aircraft which is carried aloft and air launched by a larger carrier aircraft or mother ship to support the primary mission of the carrier. The carrier craft may or may not be able to later recover the parasite during flight.

The first parasite aircraft flew in 1916, when the British launched a Bristol Scout from a Felixstowe Porte Baby flying boat. The idea eventually developed into jet bombers carrying fully capable parasite fighters. With the advent of long-range fighters equipped with air-to-air missiles, and aerial refueling, parasite fighters fell out of use.

Type 2 machine gun

The Type 2 machine gun was developed for aerial use for the Imperial Japanese Navy during World War II. It was an adaptation of the German MG 131 machine gun.

Type 92 machine gun

The Type 92 7.7mm machine gun (九二式七粍七機銃, Kyūni-shiki nana-miri-nana kijū) was developed for aerial use for the Imperial Japanese Navy in 1932. The Type 92 is a light machine gun and not to be confused with the similarly named Type 92 Heavy Machine Gun.

Type 99 cannon

The Type 99 Mark 1 machine gun and Type 99 Mark 2 machine gun were Japanese versions of the Oerlikon FF and Oerlikon FFL autocannons. They were adopted by the Imperial Japanese Navy (IJN) in 1939 and served as their standard aircraft autocannon during World War II.

World War II Allied names for Japanese aircraft

The World War II Allied names for Japanese aircraft were reporting names, often described as codenames, given by Allied personnel to Imperial Japanese aircraft during the Pacific campaign of World War II. The names were used by Allied personnel to identify aircraft operated by the Japanese for reporting and descriptive purposes. Generally, Western men's names were given to fighter aircraft, women's names to bombers, transports, and reconnaissance aircraft, bird names to gliders, and tree names to trainer aircraft.

The use of the names, from their origin in mid-1942, became widespread among Allied forces from early 1943 until the end of the war in 1945. Many subsequent Western histories of the war have continued to use the names.

Yokosuka P1Y

The Yokosuka P1Y Ginga (銀河, "Galaxy") was a twin-engine, land-based bomber developed for the Japanese Imperial Navy in World War II. It was the successor to the Mitsubishi G4M and given the Allied reporting name "Frances".

Company designations
Imperial Japanese Army early designations
Imperial Japanese Army short designations
Imperial Japanese Navy short designations
World War II Allied reporting names
Japanese Self-Defense Force designations
Imperial Japanese Navy Air Service land-based bomber designations
Aircraft in Japanese service
Foreign aircraft erroneously thought to be in Japanese service


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