Mitsubishi G4M 'Betty'
Codenamed 'Betty' by the Allies, the Mitsubishi G4M long-range medium bomber remained in service with the Japanese navy from the first to the last day of the war: it took part in the attack that sank the British warships HMS Prince of Wales and HMS Repulse in December 1941, and it carried the Japanese surrender delegation on 19 August 1945. Designed to a 1937 requirement for a long-range bomber, the G4M1 prototype made its first flight on 23 October 1939, and during trials recorded an extraordinary performance of a 444-km/h (276-mph) top speed and 5555-km (3,450-mile) range, without bombload. The first production G4Mls (Navy Type 1 Attack Bomber Model 11) were initially deployed against China in mid-1941 but on the eve of the attack on Malaya the bombers moved to Indo-China and within a week had successfully attacked the Prince of Wales and Repulse.
When Allied fighter opposition eventually increased to effective proportions, the G4M1 was seen to be very vulnerable, possessing little armour protection for crew and fuel tanks, and it was in a pair of G4M1s that Admiral Yamamoto and his staff were travelling when shot down by P-38s over Bougainville on 18 April 1943. Little improvement had been secured in the Navy Type 1 Attack Bomber Model 22 with revised powerplant. The G4M2 was therefore introduced with increased armament, increased fuel and 1,800-hp (1343-kW) Mitsubishi Kasei radials, and this version (Navy Type 1 Attack Bomber Model 22A and Model 22B) remained in production until the end of the war in steadily improved Navy Type 1 Attack Bomber Model 24 variants. A further improved version, the G4M3, with increased crew protection, was also produced in small numbers as the Navy Type 1 Attack Bomber Model 34. Production amounted to 1,200 G4Mls, 1,154 G4M2s and 60 G4M3s.
Specification Mitsubishi G4M2 'Betty'
Type: seven-crew land-based naval bomber
Powerplant: two 1,800-hp (1343-kW) Mitsubishi MK4P Kasei 21 radial piston engines
Performance: maximum speed 438 km/h (272 mph) at 4600m (15,090 ft); climb to 8000 m (26,245 ft) in 32,4 minutes;
service ceiling 8950m (29,365 ft); range 6059 km (3,765 miles)
Weights: empty 8160kg (17,990 lb); normal loaded 12500 kg (27,558 lb)
Dimensions: span 25.00 m (82 ft ); length 20,00m (67 ft 7in); height 6.00m ( 19 ft 8.4in); wing area 78.125 m2 (840.93 sqft)
Armament: two 7.7-mm (0.303-in) Type 92 machine-guns in nose, one 7.7-mm (0.303-in) Type 92 machine-gun
in each side blister position, one 20-mm Type 99 cannon in dorsal turret andone 20-mm Type 99 in tail,
plus 1000 kg (2,205 lb) of bombs or one 800-kg (1,764-lb) torpedo