Mitsubishi G4M

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Mitsubishi G4M
Mitsubishi G4M of 801st Kokutai
Type	Twin-engine heavy bomber
Manufacturer	Mitsubishi
Maiden flight	23 October 1939
Retired	1945
Primary user	Imperial Japanese Navy
Number built	2,446

The Mitsubishi G4M (一式陸上攻撃機: Type 1 (usually) land-based attack aircraft, with the Allied identification name of Betty) was a twin-engined, land-based bomber aircraft used by the Imperial Japanese Navy in World War II. The bomber was nicknamed the Betty by the American military. The Americans and their allies usually dubbed male code-names on Japanese fighters and float-planes, and usually female names to Japanese bombers and reconnaissance planes.

Contents 1 Design and development 2 Operational history 3 Versions 3.1 G4M1 3.2 G4M2 3.3 G4M3 3.4 G6M1 4 Production 5 Operators 6 Specifications (Mitsubishi G4M Type 22) 7 References 8 Related content

[edit] Design and development

The "Betty" had a long range and high-speed at the time of its introduction. However, it was most known for its poorly-protected aviation gasoline tanks - that earned her the derisive monikers "one-shot lighter" and "flying Zippo" from Allied fighter pilots. This was due to the fact that on many occasions, it was used for low-altitude torpedo attacks that diminished its performance advantages. The "Betty"'s relatively-large size made it a large target to shoot at, and the simplified approach path on a torpedo run to attack a ship, meant for a generally easy interception. When used for medium to high altitude bombing against stationary targets like a supply depots, seaports, or airfields, that was another matter entirely. Using its long range and high speed, the "Bettys" could appear from any direction, and then be gone before many fighters could intercept them. Near the end of the war the "Betty" was used as a common kamikaze-carrying & launching platform, and was the usual aircraft for carrying the Ohka kamikaze rocket- aircraft.

[edit] Operational history

The "Betty" was similar in performance and missions to the other twin-engine bombers, the German Junkers Ju-88, the North American B-25 "Mitchell", and the American Martin B-26 "Marauder". These were all commonly used in the anti-shipping role, and all but the B-25 were used as torpedo-bombers. The "Betty" was prominent in attacks on Allied shipping in the 1941- early 44 time-frame, but beyond that time, she was increasingly the easy prey of the ever-improving American Navy, AAF, and USMC fighter planes, just as was all of the Japanese air power.

The "Betty" was noted for being part of the sinking of Prince of Wales and Repulse, along with the older Japanese bombers, the Mitsubishi G3M "Nells." The Prince of Wales and the Repulse were the first two battleships ever to be sunk exclusively by air attack during a war, while at sea.

Probably the best-known incident involving a G4M during the war was the successful interception of the aircraft carrying IJN Admiral Isoroku Yamamoto by American P-38 Lightnings on April 18, 1943.

As part of the negotiations for the surrender of Japan, two demilitarized Bettys, given the call-signs Bataan 1 and Bataan 2 were sent to Ie Shima carrying the first surrender delegations as the first leg of their flight to Manila.

In 1945, Indonesian guerillas captured numerous ex-Japanese air bases (several numbers of G4M Betty captured by indonesian guerillas) including Bugis Air Base in Malang (repatriated 18 September 1945). Most of the aircraft were destroyed during 1945-1949 when the former Dutch East Indies and the Netherlands were engaged in military conflict/police action in Indonesia.

[edit] Versions

[edit] G4M1

G4M1 Prototypes

Japanese Navy land Based Bomber Type 1. Two prototypes built.

G4M1 Model 11

Japanese Navy Land Attack Bomber Type 1. First bomber model of series.

G4M1 Model 12

Mitsubishi MK4E Kasei 1,530 hp (1,140 kW) engines. Several fuselage modifications.

[edit] G4M2

G4M2 Model 22

G4M1 with different engines, modified weapon load, laminar flux wings.

G4M2 Model 22A

Very similar to previous model. Armed with two type 99 20 mm cannons replacing the 7.7 mm machine guns in the lateral positions.

G4M2 Model 22B

Armed with four type 99 20 mm cannons.

G4M2a Model 24a

Modified Model 22, MK4T Kasei 25 1,800 hp (1,340 kW) engine, with bulged bomb bay doors for larger bomb capacity.

G4M2a Model 24a/b

Armament similar to model 22A/B respectively.

G4M2a Model 24c

Modified 24b, with one type 2 13 mm machine gun mounted in front nose cabin.

G4M2b Model 25

One G4M2a modified to MK4T-B Kasei 25b 1,825 hp (1,360 kW) engines. Only experimental.

G4M2c Model 26

Two G4M2a modified to MK4T-B Ru Kasei 25b 1,825 hp (1,360 kW) engines with Turbo compressors.

G4M2d Model 27

One G4M2 modified to MK4V Kasei 27 1,795 hp (1,340 kW) engines.

G4M2e Model 24J

Special version for the transport of the suicide bomb plane Kugisho/Yokosuka MXY-7 "Ohka" (Baka) Model 11, conversions of G4M2a Models 24B and 24C.

[edit] G4M3

G4M3 Model 34

Redesigned G4M2 with added self-sealing fuel tanks and improved armor protection. Redesigned wings and tail plane. Armed with two Type 92 7.7 mm machine guns in nose cabin and in both side positions, and one type 99 model 1 20 mm cannon in dorsal turret and tail. Changed maximum capacity of 1,000 kg of bombs or one 800 kg torpedo.

G4M3a Model 34A

Transport and antisubmarine version with modified armament. Only experimental.

G4M3 Model 36

Prototype. Two G4M2 Model 34 modified to Mitsubishi MK4-T Kasei 25b Ru 1,825 hp (1,360 kW) engines.

[edit] G6M1

G6M1 Japanese Navy Long Range Heavy Fighter Type 1

Initial model of the series, armed with Type 99 20 mm cannons between each side of fuselage and in tail, one 7.7 mm machine gun in nose cabin and one 30 mm cannon in front ventral position. Thirty built.

G6M1-K Trainer, Japanese Navy Type 1

Converted G6M1s.

G6M1-L2 Transport Type 1, Japanese Navy

Modified as transports.

[edit] Production

• Total production of G4M2 and Models 22A-B: 350 examples.
• Total production of G4M2a, Models 24A, 24B and 24C: 790 examples.
• Total production of G6M1-K and derived types: 1,200 examples.

• Total production of all versions: 2,446 examples.

[edit] Operators

•  Japan

[edit] Specifications (Mitsubishi G4M Type 22)

General characteristics

• Crew: 7: pilot, co-pilot, navigator/bombardier, radio operator/gunner, three gunners
• Length: 19.6 m (64 ft 4 in)
• Wingspan: 24.9 m (81 ft 8 in)
• Height: 6 m (19 ft 8 in)
• Powerplant: 2× Mitsubishi Kasei 25 radial engines, 1,380 kW (1,850 hp) each

Performance

• Maximum speed: 437 km/h (270 mph)
• Range: 4,725 km (one way) (2,935 mi)
• Service ceiling: 8,950 m (29,350 ft)

Armament

• Guns: 2x 20 mm cannons, 4x 7.7 mm machine guns
• Bombs: 800 kg (1,765 lb) of bombs or torpedoes

[edit] References

• Horodyski, Joseph M. “British Gamble In Asian Waters.” Military Heritage. December 2001. Volume 3, No. 3: 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 Two).

[edit] Related content