Mitsubishi G3M

The Mitsubishi G3M, Type 96 land-based attack aircraft, was a Japanese bomber and transport aircraft used by the Imperial Japanese Navy Air Service during World War II.

The Yokosuka L3Y (Allied reporting name “Tina”), was a transport variant of the aircraft manufactured by the Yokosuka Naval Air Technical Arsenal.

The G3M has its origins in a specification submitted to the Mitsubishi company from the Imperial Japanese Navy requesting a bomber aircraft with a range unprecedented at the time.

This principally stemmed from Admiral Isoroku Yamamoto’s influence in the Naval High Commission.

The bomber was to have the capacity to accommodate an aerial torpedo capable of sinking an armoured battleship.

The speed requirement submitted by the naval department was again also unprecedented, not only in Japanese but also in international bomber aviation, where in relation to the envisaged Japanese battlegrounds of China and the Pacific, the bomber would need to not only cover long distances, but necessarily have exceptional speed to strike distant targets with a minimum attack time.

Thus, the G3M was an embodiment of Japanese military aircraft design in the brief period leading to the Pacific War, with powerful offensive armament (in this case in the form of bombs and torpedoes) and range and speed emphasised over protection and defensive capabilities.

Even in the low-speed, low-level role of torpedo bomber, the superior fighter escort combined with the G3M’s high speed was considered sufficient against any form of ship-based AA guns or carrier-based fighters.

The lightweight structure and complete lack of defensive machine guns and the additional crew necessary to operate them (features in the early prototype design) were considered essential to maintain the speed and high-altitude performance of the G3M with a heavy payload.

Even after the modified final prototype, which did include three defensive machine gun emplacements, the G3M kept its lightweight structure and lacked any form of defensive armour or self-sealing fuel tanks, as these were considered to retard speed and altitude.

This trait in Japanese bomber and fighter design manifested itself again in its successor, the Mitsubishi G4M, whose design so strongly emphasized fuel and bomb load for long-range strikes at the expense of defence that its vulnerability to fighters and ground and surface gunfire earned it the unofficial nickname of “one shot lighter” by Allied fighter pilots.

The bombsight used in the G3M was primitive compared to the mechanisms used in the G3M’s contemporaries such as the B-17 Flying Fortress and Heinkel He 111.

Aside from the limited precision necessary in its naval role as a long-range torpedo bomber against Allied naval fleets, the G3M frequently operated with other G3M units in massive “wave” formation.

Use of these large formations eliminated the need for singular high-precision bombing attacks.

Later the Nakajima Company redesigned the G3M into the improved G3M3 (Model 23) with more powerful engines and increased fuel capacity. This version was manufactured only by Nakajima, being the most rapidly produced in wartime.

This version entered service in 1941, and was maintained in service for two years, and later used in 1943 alongside the G3M2 for long-range maritime reconnaissance with radar, due to its excellent long-range performance.

Other G3M derivations were the transport versions, G3M-L and L3Y, the latter built by Yokosuka.

Variants

Ka-15

Prototype with either Hiro Type 91 (559 kW/750 hp), Mitsubishi Kinsei 2 (619 kW/830 hp), or Mitsubishi Kinsei 3 (679 kW/910 hp) engines and glass or solid nose, 21 built.

G3M1a/c

Redesignated prototypes powered by Hiro Type 91 or Mitsubishi Kinsei engines, glass nose.

G3M1 Model 11

Land-based attack bomber navy Type 96 first series model.

Major extension of the cabin with a revised cover, some with fixed-pitch propeller, 34 built.

G3M1-L

G3M1 converted into an armed or unarmed military transport version and powered by Mitsubishi Kinsei 45 (802 kW/1,075 hp) engines.

G3M2 Model 21

More powerful engines and increased fuel capacity, dorsal turret; 343 constructed by Mitsubishi, 412 G3M2 and G3M3 manufactured by Nakajima.

G3M2 Model 22

Upper and belly turrets substituted for one upper turret, glass side positions. 238 built.

G3M3 Model 23

More powerful engines and increased fuel capacity for longer range, constructed by Nakajima.

L3Y1 Model 11

Transport navy Type 96, advanced conversion of G3M1 armed transport, built by Yokosuka.

L3Y2 Model 12

Modification of G3M2 with Mitsubishi Kinsei engines, built by Yokosuka.

Mitsubishi twin-engined transport

Around two dozen G3M2 Model 21 bombers converted for use by civil operators such as Nippon Koku K.K.

Nippon

One of the twin engined transports converted to carry out a round the world flight in 1939 on behalf of the Mainichi Shimbun newspaper.

Specifications

Crew

7

Length

16.45 m (54 ft 0 in)

Wingspan

25 m (82 ft 0 in)

Height

3.68 m (12 ft 1 in)

Wing area

75 m2 (810 sq ft)

Empty weight

4,965 kg (10,946 lb)

Gross weight

8,000 kg (17,637 lb)

Fuel capacity

3,874 l (852.2 imp gal; 1,023.4 US gal)

Powerplant

2 × Mitsubishi Kinsei 14-cyl,

Air-cooled radial piston engines,

791 kW (1,061 hp) each

Performance

Maximum speed

375 km/h (233 mph, 202 kn)

Cruise speed

280 km/h (170 mph, 150 kn)

Range

4,400 km (2,700 mi, 2,400 nmi)

Service ceiling

9,200 m (30,200 ft)

Rate of climb

6 m/s (1,200 ft/min)

Armament

Guns

1× 20 mm (0.79 in) Type 99 cannon in rear dorsal turret

4× 7.7 mm (0.30 in) Type 92 machine gun in cockpit,

Left and right-side positions,

And in retractable forward dorsal turret.

Bombs

800 kg (1,800 lb) of bombs or one aerial torpedo.