The A-20G variant was produced in greater numbers than any other A-20 variant. A total of 2850 were built at the Douglas Santa Monica plant from 1943 to 1944.
The A-20G was first ordered on June 1, 1942 and first delivered in February of 1943. It introduced a solid nose armed with four 20-mm M2 cannon with 60 rpg and two 0.50-inch machine guns with 350 rpg. The four cannon were grouped in the forward part of the nose and projected well forward of the nose, with the two machine guns further back in the lower part of the nose. This new nose was introduced as a result of combat experience in the Pacific, where glass-nosed A-20s had been fitted with field modifications to increase their forward firepower during low-level strafing missions. The new nose made the A-20G slightly longer than previous variants. The A-20G retained the 0.5-inch flexible machine gun with 500 rounds in the rear cockpit, as well as the 0.30-in or 0.50-inch tunnel gun. The dorsal gunner's position was no longer equipped with emergency flight controls, and provision for photographic equipment was also deleted. Heavier-gauge armor plate was used, adding some 400 pounds to the weight. Carburetor deicing equipment was added.
However, the 20-mm nose cannon had a slow rate of fire and were prone to jamming, and after 250 aircraft were completed, the four cannon were replaced by four 0.50-inch machine guns beginning with the A-20G-5-DO production block. The two 0.50-inch machine guns were retained, and the total number of forward-firing machine guns was now six. Most of the cannon-armed A-20G-1-DO aircraft were eventually turned over to the Soviet Union.
Production block A-20G-10-DO introduced an improved carburetor air filter. Block -15 introduced heating for winter operations and some electrical changes.
With production block A-20G-20-DO, an electrically-driven manned Martin power turret equipped with two 0.50-inch machine guns was introduced in place of the single hand-held machine gun in the rear compartment. To accommodate this new turret, the fuselage had to be widened by six inches in the area of the gunner's compartment. The turret could rotate 360 degrees, and the guns could be elevated from horizontal to directly upwards. At the same time, the 0.30-inch machine gun in the ventral tunnel position was replaced by a 0.50- inch gun. Also introduced on block -20 was a pair of bomb racks stressed to carry 500-lb bombs underneath the outer wing panels. Internal fuel capacity was increased from 540 US gallons to 725 gallons, and provision was made for the mounting of a 374-gallon drop tank underneath the fuselage.
A-20G-25-DO introduced several minor changes such as sealed beams for the landing lights and a pilot seat made of non-strategic materials. One example (43-9230) was diverted to become the A-20J prototype.
A-20G-30-DO introduced an improved collection system for spent cartridges, and heavier-gauge skin on the stabilizer was introduced on A-20G-35-DO. A modified engine exhaust system was introduced on A-20G-40-DO, and the provision for the carriage of a torpedo was finally deleted. The A-20G-45-DO, final production block of the G-series, had retainer boxes installed to keep expended machine gun shells from falling out of the aircraft.
Most of the A-20G-1-DOs, as well as a large number of later A-20G variants were delivered to the Soviet Union. Many of the later Soviet A-20Gs had their Martin turrets replaced by Russian-built rear turrets
There is an A-20G on display at the USAF Museum at Wright-Patterson AFB in Dayton, Ohio. It is painted as A-20G-45-DO serial number 43-22200.
42-53535/53784 Douglas A-20G-1-DO Havoc 42-53785/53834 Douglas A-20G-5-DO Havoc 42-53835/54134 Douglas A-20G-10-DO Havoc 54057/54062, 54064/54068, 54103, 54105/54106, 654108/54110, 54112, 54126/54129, 654131/54134 converted to P-70A-1 night fighter. 54069 to RAAF as A28-69. Returned to USAAF 1/45 54073 to RAAF as A28-71. Returned to USAAF 1/45 54091 to RAAF as A28-70. Returned to USAAF 1/45 54092 to RAAF as A28-72. Returned to USAAF 1/45 54098 to RAAF as A28-73. Returned to USAAF 1/45 54120 to RAAF as A28-74. Returned to USAAF 1/45 42-54135/54284 Douglas A-20G-15-DO Havoc 54135/54142, 54161, 54163/54165, 54267/54274 converted to P-70A-1 night fighter. 42-86563/86912 Douglas A-20G-20-DO Havoc 86858, 86893, 86896, 86900/86902, 86904/86911 modified as P-70B-2 night fighter 86786 forced down due to bad weather in April 1944. Retrieved by RAAF near Annamoin Sept 1984 for restoration and ultimate return to Papua New Guinea. 43-9231/9437 Douglas A-20G-25-DO Havoc 43-9458/9637 Douglas A-20G-30-DO Havoc 43-9665/9837 Douglas A-20G-30-DO Havoc 9682, 9727/9728, 9732, 9737, 9739, 9784/9789 converted to P-70B-2 night fighter 43-9838/9856 Douglas A-20G-35-DO Havoc 43-9881/9909 Douglas A-20G-35-DO Havoc 43-9918/10104 Douglas A-20G-35-DO Havoc 9992, 10000, 10004 converted to P-70B-2 night fighter 43-10145/10237 Douglas A-20G-35-DO Havoc 43-21252/21431 Douglas A-20G-40-DO Havoc 21294 to RAAF as A28-58 6/44. Returned to USAAF 1/45. 21296 to RAAF as A28-50 6/44. Crashed in sea 09/44 21301 to RAAF as A28-57 6/44. Damaged in air raid 11/44, returned to USAAF 1/45. 21303 to RAAF as A28-55 6/44. Lost in action 9/44 21306 to RAAF as A28-51 6/44. Damaged in air raid 11/44, converted to components. 21308 to RAAF as A28-52 6/44. Damaged in air raid 11/44, converted to components. 21311 to RAAF as A28-53 6/44. missing on ops 9/44. 21314 to RAAF as A28-56 6/44. Returned to USAAF 3/45. 21380 to RAAF as A28-61 7/44. Missing on test flight 9/44. 21381 to RAAF as A28-62 7/44. Damaged in accident 1/45, returned to USAAF. 21384 to RAAF as A28-63 7/44. Damaged in crash landing 9/44, converted to components. 21387 to RAAF as A28-64 7/44. Returned to USAAF 1/45. 43-21472/21551 Douglas A-20G-40-DO Havoc 21540 to RAAF as A28-54 6/44. Damaged in air raid 11/44. 21542 to RAAF as A28-59 6/44. Damaged in air raid 11/44, converted to components. 21545 to RAAF as A28-60 6/44. Damaged in air raid 11/44, converted to components. 21551 converted to P-70B-2 night fighter 43-21582/21701 Douglas A-20G-40-DO Havoc 43-21752/21827 Douglas A-20G-45-DO Havoc 43-21878/21987 Douglas A-20G-45-DO Havoc 21953 to RAAF as A28-65 8/44. Damaged in air raid 11/44, converted to components. 21970 to RAAF as A28-75 10/44. Damaged in air raid 11/44, converted to components. 21976 to RAAF as A28-66 8/44. Returned to USAAF 1/45. 21977 to RAAF as A28-67 8/44. Damaged in air raid 11/44, converted to components. 21978 to RAAF as A28-76 10/44. Damaged in air raid 11/44, converted to components. 21985 to RAAF as A28-68 8/44. Damaged in air raid 11/44, converted to components. 43-22148/22251 Douglas A-20G-45-DO Havoc 22250 to to RAAF as A28-77 10/44. Returned to USAAF 2/45.
Engines: Two 1600 hp Wright R-2600-23 Double Cyclone 14 cylinder twin-row
air-cooled radial engines equipped with two-speed superchargers.
Rated at 1600 hp for takeoff, 1675 hp war emergency, and 1400 hp at
Performance: Maximum speed 339 mph at 12,400 feet, 317 mph at 10,000
feet. Cruising speed 230-272 mph. Initial climb rate 1300 feet per
minute. An altitude of 10,000 feet could be attained in 7.1 minutes.
Service ceiling 25,800 feet. Range 1025 miles with 2000-lb bombload
at 238 mph. Maximum ferry range 2035 miles..
Dimensions: Wingspan 61 feet 4 inches, length 48 feet 0 inches,
height 17 feet 7 inches, wing area 465 square feet.
Weights: 17,200 pounds empty, 24,000 pounds normal combat takeoff,
maximum combat 27,200 pounds, 30,000 pounds maximum.
Armament: Six forward-firing 0.50 Colt-Browning machine guns in the
nose with 350 rpg. Two 0.50-inch machine gun in dorsal power turret
with 400 rpg. One 0.50-inch machine gun in the ventral tunnel
position with 400 rounds. Models prior to A-20G-20-DO had two
0.50-inch machine guns on a flexible dorsal mount. Maximum internal bomb
load 2000 pounds in split bomb bay plus (on later models) 2000 pounds
on four underwing hardpoints.