bombers

bombers. (For carrier aircraft, see carriers, 2.)

1. Design and development

Most of the bombers in service in 1939 were twin-engined all-metal monoplanes with bomb loads of 454–2,040 kg. (1,000–4,500 lb.) and, for the larger machines, a range of up to 4,025 km. (2,500 mi.).

Germany started with three main types, early versions of which had been tested in the Spanish Civil War: the Heinkel He111, the smaller and faster Dornier Do17, and the single-engined Junkers Ju87 dive-bomber (or ‘Stuka’). All had a weak defensive armament of hand-trained machine-guns and were vulnerable to modern fighters. German aircraft, however, were the first to be fitted with self-sealing fuel tanks.

Purpose designed and stressed, the Ju87 remained stable in a nearly vertical dive and could hit targets with great accuracy. Just entering service, the twin-engined Ju88 was fast and manoeuvrable, had a strong structure, and had been modified during development to undertake dive-bombing; it proved to be the most versatile German aircraft of the war.

Fully comparable with the German bombers was Poland's P.Z.L. P37 Łoś, which could carry a bigger load of bombs than its own empty weight, but only 36 of these machines were in service. France, caught with a fleet of antiquated bombers, was re-equipping (too late) with new types such as the Lioré et Olivier LeO451, the fastest of all bombers in 1939.

The fighting in May– June 1940 which preceded the fall of France revealed the inadequacy of Britain's Fairey Battle single-engined day bombers; too slow and without fighter escort, they suffered appalling losses. Smallest and fastest of the British twin-engined bombers was the Bristol Blenheim, past its prime but bearing the brunt of daylight operations. It was backed by three ‘heavy’ bombers: the Armstrong Whitworth Whitley, Handley Page Hampden, and Vickers-Armstrongs Wellington. The most outstanding of these was the Wellington whose unusual structure—fabric covering over a geodetic light-alloy framework—was immensely strong, could absorb massive battle damage, and was an efficient load-carrier over long distances. Like most British bombers, the Wellington had power-operated gun turrets (pioneered by the UK from 1934 onwards), but even these proved inadequate on unescorted daylight raids, hence RAF Bomber Command's switch to night bombing during the strategic air offensive against Germany.

Bombers, 1: Principal bomber aircraft types

Type	Crew	Powerplant	Wing Span	Loaded Weight	Max Speed	Service Ceiling	Range	Armament	Remarks
In many cases the bomb load quoted is the maximum that could be accommodated, but this was reduced if the range was increased. Towards the end of the waron raids on Berlin the RAF's Mosquito (2 crew) and the USAAF's B17G Fortress (10 crew) delivered exactly the same bomb load —1,814 kg (4,000 lb).
Source: Contributor.
1. France
Lioré et	4	2 × 1,060 hp	22.52 m	11,400 kg	480 km/h	9,000 m	2,900 km	1,400 kg	373 delivered by
Olivier		Gnome-Rhone	(73 ft 10.1/2 in)	(25,132 lb)	(298 mph)	(29,530 ft)	(1,802 miles)	(3,086 lb);	armistice. Continued
LeO451		14N						1 20 mm	in production for
								cannon and	Vichy French Air
								5 × 7.5 mm mg	Force.
2. Germany
Heinkel	5	2 × 1,340 hp	22.60 m	11,338 kg	415 km/h	7,775 m	2,820 km	2,500 kg	Approx. 7,300 built.
He111H-6		Jumo 211F	(74 ft 1 3/4 in)	(25,000 lb)	(258 mph)	(25,500 ft)	(1,740 miles)	(5,510 lb)	Served throughout
								bombs;	war.
								1 × 20 mm
								cannon and
								6 × 7.9 mm
								machine-guns
Dornier	4	2 × 1,000 hp	18.00 m	8,590 kg	410 km/h	8,200 m	1,360 km	1,000 kg	Approx. 1,100 built
Do17Z-2		Bramo 323P	(59 ft 5/8 in)	(18,937 lb)	(255 mph)	(26,900 ft)	(845 miles)	(2,205 lb)	(all versions).
								bombs;	Phased out 1942.
								4-8 × 7.9 mm mg
Junkers	2	1 × 1,200 hp	13.80 m	4,335 kg	383 km/h	8,000 m	790 km	500 kg (1,102 lb)	5,709 built. The
Ju87B-2		Jumo 211 Da	(45 ft 3 1/3 in)	(9,560 lb)	(238 mph)	(26,250 ft)	(490 miles)	bombs;	‘Stuka’ dive-bomber.
								3 × 7.9 mm mg	Later used as
									tank-buster. Served
									throughout war.
Junkers	4	2 × 1,340 hp	20.00 m	14,000 kg	470 km/h	8,200 m	1,780 km	3,000 kg (6,614 lb)	14,676 built, of
Ju88A-4		Jumo 211J	(65 ft 7 1/2 in)	(30,684 lb)	(292 mph)	(26,900 ft)	(1,106 miles)	bombs;	which approx,
								6 × 7.9 mm mg	9,000 were
									bombers. Served
									throughout war.
Dornier	4	2 × 1,580 hp	19.00	14,998 kg	515 km/h	7,500 m	2,300 km	4,000 kg (8,818 lb)	1,905 built (all
Do217E-2		BMW 801L	(62 ft 4 in)	(33,070 lb)	(320 mph)	(24,600 ft)	(1,430 miles)	bombs;	versions).
								1 × 15 mm cannon,	Operational March
								2 × 13 mm and	1941.
								3 × 7.9 mm mg
Junkers		2 × 1,600 hp	22.00 m	14,510 kg	500 km/h	9,300 m	1,950 km	3,000 kg (6,614 lb)	1,076 built (all
Ju188E-1	5	BMW 801ML	(72 ft 2 in)	(31,989 lb)	(311 mph)	(31,510 ft)	(1,211 miles)	bombs;	versions).
								2 × 20 mm cannon,	Operational August
								and 2 × 13 mm mg	1943. Derived
									from Ju88.
Heinkel	6	2 × 3,100 hp	31.44 m	31,000 kg	488 km/h	8,000 m	4,990 km	6,000 kg (13,228 lb)	1,146 built.
He177A-5		Daimler-Benz	(103 ft 1 3/4 in)	68,342 lb	(303 mph)	(26,245 ft)	(3,100 miles)	bombs;	Operational late
		DB610 coupled						2 × 20 mm cannon,	1942. Long-range
		engines						3 × 13 mm and	strategic bomber.
								3 × 7.9 mm mg
Arado	1	2 × 1,764 lb-	14.44 m	9,800 kg	742 km/h	10,000 m	1,630 km	2,200 kg (4,409 lb)	Approx. 210 built.
Ar234B-2		thrust BMW	(46 ft 3 1/2 in)	(21,605 lb)	(461 mph)	(32,810 ft)	(1,013 miles)	bombs;	World's first jet
		003A-1						2 × 20 mm cannon	bomber. Operational
									November 1944.
3. Italy
Savoia-	4/5	3 × 780 hp	21.20 m	10,725 kg	430 km/h	6,500 m	3,300 km	1,250 kg (2,755 lb)	1,330 built. Later
Marchetti		Alfa Romeo	(69 ft 6 1/2 in)	(23,644 lb)	(267 mph)	(21,325 ft)	(2,050 miles)	bombs;	used as torpedo-
SM79		126RC34						3 × 12.7 mm and	bomber.
								1 × 7.7 mm mg
Fiat	5/6	2 × 1,000 hp	21.56 m	10,448 kg	430 km/h	7,600 m	2,000 km	1,600 kg (3,527 lb)	Approx. 600 built.
BR20M		Fiat A.80 RC41	(70 ft 8 3/4 in)	(23,038 lb)	(267 mph)	(24,935 ft)	(1,243 miles)	bombs;	Used for raids on
								1 × 12.7 mm and	Britain, November
								2 × 7.7 mm mg	1940.
CRDA	5	3 × 1,000 hp	24.80 m	13,621 kg	450 km/h	8,100 m	2,657 km	3,000 kg (6,615 lb)
(Cant)		Piaggio P.Xlbis	(81 ft 4 1/2 in)	(30,029 lb)	(280 mph)	(26,575 ft)	(1,650 miles)	bombs;	Approx. 660 built.
Z1007bis		RC40						2 × 12.7 mm and
								2 × 7.7 mm mg
4. Japan
Mitsubishi	5	2 × 1,500 hp	22.50 m	10,610 kg	486 km/h	10,000 m	2,700 km	1,000 kg (2,205 lb)	Approx. 2,060
Ki21 IIb		Mitsubishi	(73 ft 9 3/4 in)	(23,391 lb)	(302 mph)	(32,810 ft)	(1,680 miles)	bombs;	built. Army
(‘Sally’)		Ha-101						1 × 12.7 mm and	bomber.
								4 × 7.7 mm mg
Mitsubishi	7	2 × 1,800 hp	25.00 m	12,500 kg	438 km/h	8,950 m	6,059 km	1,000 kg (2,205 lb)	2,414 built.
G4M2		Mitsubishi	(82 ft 1/4 in)	(27,558 lb)	(272 mph)	(29,365 ft)	(3,765 miles)	bombs,	Land-based
(‘Betty’)		MK4P Kasei 21						or torpedo;	navy bomber. Also
								2 × 20 mm cannon	carried ohka (Baka)
								and 4 × 7.7 mm mg	suicide bomb.
Mitsubishi	6/8	2 × 1,900 hp	22.50 m	13,765 kg	537 km/h	9,470 m	2,800 km	1,070 kg (2,360 lb)	698 built.
Ki67		Mitsubishi	(73 ft 9 3/4 in)	(30,347 lb)	(334 mph)	(31,070 ft)	(1,740 miles)	bombs;	Army bomber;
(‘Peggy’)		Ha-104						1 × 20 mm cannon	also used by navy as
								and	torpedo-bomber.
								4 × 12.7 mm mg	Entered service
									October 1944.
5. Poland
P.Z.L.	4	2 × 918 hp	17.93 m	8,560 kg	445 km/h	6,000 m	2,600 km	2,200 kg (4,850 lb)	108 built. Max.
P.37 Loś B		Bristol	(58 ft 10 in)	(18,872 lb)	(276 mph)	(19,680 ft)	(1,615 miles)	bombs;	bomb load
		Pegasus XX						3 × 7.7 mm mg	3,020 kg
									(6,657 lb)
6. UK
Fairey	3	1 × 1,030 hp	16.46 m	4,895 kg	388 km/h	7,165 m	1,690 km	454 kg (1,000 lb)	2,203 built.
Battle I		Rolls-Royce	(54 ft 0 in)	(10,792 lb)	(241 mph)	(23,500 ft)	(1,050 miles)	bombs;	Proved ineffective
		Merlin III						2 × 0.303 in mg	in France, May 1940;
									used mainly for
									training thereafter.
Bristol	3	2 × 920 hp	17.17 m	6,530 kg	428 km/h	6,705 m	2,350 km	454 kg (1,000 lb)	Approx. 6,200 built
Blenheim IV		Bristol	(56 ft 4 in)	(14,400 lb)	(266 mph)	(22,000 ft)	(1,460 miles)	bombs;	(all versions).
		Mercury XV						3-5 × 0.303 in mg	Withdrawn from
									bomber operations
									1943.
Armstrong	5	2 × 1,145 hp	25.60 m	15,196 kg	357 km/h	5,365 m	2,655 km	1,360 kg (3,000 lb)	1,676 built. Max.
Whitworth		RR	(84 ft 0 in)	(33,500 lb)	(222 mph)	(17,600 ft)	(1,650 miles)	bombs;	bomb load 3,175 kg
Whitley V		Merlin X						5 × 0.303 in mg	(7,000 lb). Last
									bombing raid April
									1942.
Handley	4	2 × 1,000 hp	21.08 m	9,526 kg	409 km/h	5,790 m	1,931 km	1,814 kg (4,000 lb)	1,430 built. Last
Page		Bristol	(69 ft 2 in)	(21,000 lb)	(254 mph)	(19,000 ft)	(1,200 miles)	bombs;	bombing raid
Hampden I		Pegasus XVIII						6 × 0.303 in m.g.	September 1942.
Vickers	6	2 × 1,500 hp	26.26 m	15,422 kg	411 km/h	5,790 m	2,478 km	2,041 kg (4,500 lb)	11,461 built (all
Wellington III		Bristol	(86 ft 2 in)	(34,000 lb)	(255 mph)	(19,000 ft)	(1,540 miles)	bombs;	versions). Last bombing
		Hercules XI						8 × 0.303 in mg	raid March 1945.
Short	7/8	4 × 1,650 hp	30.20m	31,790 kg	435 km/h	5,180 m	949 km	6,350 kg (14,000 lb)	2,374 built. Range
Stirling III		Bristol	(99 ft 1 in)	(70,000 lb)	(270 mph)	(17,000 ft)	(590 miles)	bombs;	3,237 km (2,010 mi)
		Hercules XVI						8 × 0.303 in mg	with reduced bomb
									load. Operational
									February 1941.
Handley	7	4 × 1,800 hp	31.75 m	29,480 kg	496 km/h	6,705 m	2,028 km	5,896 kg (13,000 lb)	6,176 built.
Page		Bristol	(104 ft 2 in)	(65,000 lb)	(308 mph)	(22,000 ft)	(1,260 miles)	bombs;	Operational
Halifax VI		Hercules 100						9 × 0.303 in mg	March 1941.
Avro	7	4 × 1,460 hp	31.09 m	30,845 kg	462 km/h	7,470 m	2,671 km	6,350 kg (14,000 lb)	7,377 built. Max.
Lancaster I		RR Merlin XX	(102 ft 0 in)	(68,000 lb)	(287 mph)	(24,500 ft)	(1,660 miles)	bombs;	bomb load 9,979 kg
								8 × 0.303 in mg	(22,000 lb)
									Operational
									March 1942.
De Havilland	2	2 × 1,680 hp	16.51 m	10,430 kg	668 km/h	11,887 m	2,206 km	1,814kg (4,000 lb)	7,781 built (all
Mosquito XVI		RR	(54 ft 2 in)	(23,000 lb)	(415 mph)	(39,000 ft)	(1,370 miles)	bombs;	versions).
		Merlin 72						no defensive	Operational May
								weapons	1942.
7. USA
Boeing	10	4 × 1,200 hp	31.62 m	29,025 kg	462 km/h	10,850 m	3,220 km	2,722 kg (6,000 lb)	12,731 built. Max.
B17G		Wright	(103 ft 9 in)	(64,000 lb)	(287 mph)	(35,600 ft)	(2,000 miles)	bombs;	bomb load 7,983 kg
Fortress		Cyclone						13 × 0.50 in mg	(17,600 lb) for short
		R-1820-97							missions
Douglas	3	2 × 1,600 hp	18.69 m	12,338 kg	546 km/h	7,865 m	1,754 km	1,179 kg (2,600 lb)	7,385 built. A-20G
A20G		Wright	(61 ft 4 in)	(27,200 lb)	(339 mph)	(25,800 ft)	(1,090 miles)	bombs;	version equivalent
Havoc		R-2600-23						8 × 0.50 in mg	to RAF Boston IV.
Consolidated	8/10	4 × 1,200 hp	33.53 m	29,484 kg	467 km/h	8,535 m	3,688 km	3,992 kg (8,800 lb)	18,313 built (most
B24J		Pratt & Whitney	(110 ft 0 in)	(65,000 lb)	(290 mph)	(28,000 ft)	(2,290 miles)	bombs;	numerous US
Liberator		R-1830-65						10 × 0.50 in mg	warplane in history).
North	6	2 × 1,700 hp	20.60 m	15,876 kg	438 km/h	7,375 m	2,173 km	2,720 kg (6,000 lb)	Approx. 11,400 built.
American		Wright	(67 ft 7 in)	(35,000 lb)	(272 mph)	(24,200 ft)	(1,350 miles)	bombs;	Operational February
B25J		R-2600-92						12 × 0.50 in mg	1942.
Mitchell
Martin	7	2 × 2,000 hp	21.64 m	15,513 kg	454 km/h	6,615 m	1,850 km	1,361 kg (3,000 lb)	5,157 built.
B26C		Pratt &	(71 ft 0 in)	(34,200 lb)	(282 mph)	(21,700 ft)	(1,150 miles)	bombs;	Operational April
Marauder		Whitney						12 × 0.50 in mg	1942.
		R-2800-43
Douglas	3	2 × 2,000 hp	21.35 m	15,880 kg	572 km/h	6,735 m	2,253 km	1,814 kg (4,000 lb)	2,446 built during
A26B		Pratt &	(70 ft 0 in)	(35,000 lb)	(355 mph)	(22,100 ft)	(1,400 miles)	bombs;	war. Operational
invader		Whitney						10 × 0.50 in mg	November 1944.
		R-2800-79
Boeing	10	4 × 2,200 hp	43.46 m	64,003 kg	550 km/h	9,695 m	6,598 km	5,442 kg (12,000 lb)	3,970 built.
B29A		Wright	(142 ft 3 in)	(141,000 lb)	(342 mph)	(31,800 ft)	(4,100 miles)	bombs;	Operational June
Superfortress		R-3350-57						1 × 20 mm cannon	1944. Served solely
								and 12 × 0.50 in mg	in Far East. Max.
									bomb load 9,072 kg
									(20,000 lb)
8. USSR
Tupolev	3	2 × 1,100 hp	20.33 m	7,800 kg	450 km/h	10,400 m	1,600 km	1,000 kg (2,205 lb)	Approx. 6,660 built.
SB2bis		Klimov	(66 ft 8 1/2 in)	(17,196 lb)	(280 mph)	(34,120 ft)	(994 miles)	bombs;	Original version first
		M-100A						4 × 7.62 mm mg	flew 7 October 1934.
Ilyushin	4	2 × 1,100 hp	21.44 m	10,000 kg	411 km/h	10,000 m	3,587 km	2,500kg (5,510 lb)	Approx. 6,800 built.
II4		Tumansky	(70 ft 4 1/4 in)	(22,046 lb)	(255 mph)	(32,810 ft)	(2,228 miles)	bombs;	Wood replaced much
		M-88B						3 × 12.7 mm mg	of metal structure in
									late-war production.
Petlyakov	3	2 × 1,260 hp	17.16 m	8,495 kg	580 km/h	8,800 m	1,200 km	1,000 kg (2,205 lb)	11,427 built. Fitted
Pe2		Klimov M-105PF	(56 ft 3 1/2 in)	(18,728 lb)	(360 mph)	(28,870 ft)	(746 miles)	bombs;	with brakes for
								4 × 12.7 mm and	shallow dive-
								2 × 7.62 mm mg	bombing.
Tupolev Tu2	4	2 × 1,850 hp	18.86 m	12,800 kg	550 km/h	9,500 m	2,500 km	2,270kg (5,004 lb)	Entered service 1943.
		Shvetsov	(61 ft 10 1/2 in)	(28,219 lb)	(342 mph)	(31,170 ft)	(1,553 miles)	bombs;
		ASh-82FN						2 × 20 mm cannon
								and 3 × 12.7 mm mg
Ilyushin	2	1 × 1,770 hp	14.60 m	6,360 kg	404 km/h	6,000 km	600 km	600 kg (1,321 lb)	36,000-plus built.
Il2m3		Mikulin	(48 ft 0 1/2 in)	(14,021 lb)	(251 mph)	(19,685 ft)	(373 miles)	bombs and/or	The ‘Shturmovik’
		AM-38F						rockets; 2 × 23 mm	ground-attack
								cannon, 1 × 12.7 mm	aircraft. Initial version
								and 2 × 7.62 mm mg	was a single-seater.

Italy's principal bomber, the Savoia-Marchetti SM79, had three engines (offsetting low unit power), was built largely of wood to conserve metals, and on replacement by the larger Cant Z1007—another trimotor of wooden construction—was used very successfully as a torpedo-bomber. In between was the twin-engined Fiat BR20 of metal construction and unimpressive performance. Defensive armament of the Italian machines was weak.

Soviet bombers, apart from the long-range Ilyushin Il4, were used mainly for army support. Twin-engined tactical types included the obsolete Tupolev SB2 (first used in Spain), which was succeeded by the Petlyakov Pe2—a fast machine capable of shallow dive-bombing—and, from 1943, by the larger and more heavily armed Tupolev Tu2. A unique type, built in greater numbers than any other warplane, was the single-engined Ilyushin Il2 ‘Shturmovik’ (assault aircraft), which had an armoured ‘bath’ to protect engine and crew against ground fire.

In early 1941 the UK introduced two types of four-engined bombers, the Short Stirling and Handley Page Halifax, and in March 1942 the Avro Lancaster, the finest night heavy bomber of the war, became operational. In general, these machines carried double the bomb load of foreign designs—the Lancaster a record 9,979 kg. (22,000 lb.). Also operational in 1942 was the all-wood twin-engined de Havilland Mosquito which was unarmed and relied on its speed—over 645 kmph (400 mph)—to escape interception; its loss rate was the lowest of any bomber.

Germany made less progress. The Dornier Do217 was a new design with four times the Do17's bomb load, the Ju188 was simply a development of the Ju88, and the Heinkel He177—an attempt at a long-range heavy bomber—suffered from over-complication (notably its pairs of coupled engines) and saw little effective use. Few of Germany's many advanced projects came to fruition, an exception being the Arado AR234. This carried a bomb load of 1,500 kg. (3,308 lb.) and was the world's first jet bomber when it was first delivered in June 1944. Powered by two Junkers Jumo jet engines, its speed (730 km/h. or 457 mph) put it almost beyond reach.

Prominent in the Pacific war was the Japanese Navy's Mitsubishi G4M (Allied codename ‘Betty’), a land-based twin-engined bomber which achieved its exceptional range of 6,059 km. (3,765 mi.) at the cost of light construction and poor protection for the crew and fuel tanks. Comparable army types were the less impressive Mitsubishi Ki21 (‘Sally’) and, from October 1944, the fast and manoeuvrable Mitsubishi Ki67 (‘Peggy’).

In 1935 the USA produced the first truly modern all-metal four-engined monoplane bomber, the Boeing B17 which, because of its five gun positions, was nicknamed ‘Flying Fortress’. A robust machine designed to fly at high altitudes, its armament of hand-trained guns was deceptively weak. Between then and mid-1942, when the USAAF embarked on its unescorted daylight raids, the Fortress's armament was progressively increased (thirteen 0.5 in. (12.7 mm.) guns on the B17G), but at the expense of range and/or bomb load.

First used in action by the French in May 1940, the Douglas DB7 (RAF Boston, USAAF A20 Havoc) was a fast, twin-engined attack bomber with a tricycle undercarriage, a feature perpetuated on most subsequent US bomber designs. Later, and larger, twin-engined bombers were the North American B25 Mitchell, Martin B26 Marauder, and Douglas A26 Invader.

The four-engined Consolidated B24 Liberator of 1939 had, thanks to its high aspect ratio Davis wing, a very long range and was first used by the RAF on anti-submarine patrols, helping to close the air gap in the Atlantic. More Liberators—18,313 of them—were built during the war than any other US type.

Culmination of US bomber design and produced specifically for the Pacific war was the Boeing B29 Superfortress, which could carry a 2,268 kg. (5,000 lb.) load of bombs 5,233 km. (3,250 mi.). Twice as heavy as a Lancaster, the B29 operated at high altitude, had pressurized cabins for its crew, and used remotely controlled gun turrets. This was the aircraft that dropped the atomic bombs on Japan.

David Dorrell

2. Tactics

The 1930s brought a rapid advance not only in the design of bombers but in the theories and tactics of how they were to be used; and for the Germans, in particular, participation in the Spanish Civil War gave the Luftwaffe an early chance to test many of its new ideas in combat.

Broadly speaking, the bomber of the Second World War was employed strategically (attacks on an adversary's communications, factories, sources of supply, civilian population), or tactically (attacks on an adversary's armed forces in support of one's own, and on an adversary's lines of communication and such specific targets as shipping).

The best demonstration of the tactical use of a bomber early in the war was the use of the German Junkers Ju87 dive-bomber. It was the spearhead of the blitzkrieg which proved so successful during the Polish campaign of September 1939 and in the fighting which led to the fall of France in June 1940. Its task was to destroy strong-points in the path of the advancing ground forces and it did so with pinpoint accuracy—within 30 m. (100 ft.) of its target—by diving vertically at it. It then released its bomb(s) at low altitude at the bottom of its dive, a method that proved four times more accurate than normal horizontal bombing from altitude.

The RAF had no effective army support bomber during the fighting in France. This lack was rectified in 1941 during the Western Desert campaigns when Hurricane fighters were equipped to carry bombs. Their success led later to the widescale employment of the RAF Typhoon and the P47 Thunderbolt and P51 Mustang of the US Army Air Forces (USAAF) in the role of fighter-bombers (see Figure 1), and these were often employed in cab ranks. Each could carry a bomb- or rocket-load of up to 907 kg. (2,000 lb.)—twice that of many 1939 twin-engined bombers—and after the load had been released the aircraft had the performance and manoeuvrability to defend itself.

Another tactic for supporting ground troops was developed by Air Chief Marshal Tedder in the Middle East, and came to be known as ‘Tedder's Carpet’. It was not unlike a rolling barrage (see artillery, 2), in that bombers saturated the ground ahead of the advancing forces with high-explosive and napalm bombs, and was used to help the Allied break-out (COBRA) from the Normandy beachhead during the Normandy campaign. After a preliminary bombardment by fighter-bombers, 1,500 US heavy bombers dropped 3,000 tons of bombs on German positions around St Lô. On both occasions some dropped short killing 100 servicemen, including Lt-General Lesley McNair, and wounding 600 others, but it was very effective in clearing the way for the advancing infantry and tanks, and certainly contributed to the success of the operation.

Strategic bombing demanded defensive, not offensive, tactics and the Luftwaffe bombers which raided British cities in daylight in the battle of Britain flew in formations designed to give the maximum mutual protection; this proved of little avail, however, and the bombers were later provided with fighter escorts where possible. Single bombers were, also used to mount ‘tip-and-run’ raids on any nearby coastal target and they then escaped across the Channel before British fighters could be vectored on to them. But it was the bombers employed to mount the Allied strategic air offensives that were continually forced to evolve different tactics to counter German air and ground defences. Because RAF Bomber Command mostly mounted unescorted area bombing night raids the tactics employed were different from those of the Eighth USAAF whose bombers attacked during the day using precision bombing. Initially the British bombers were widely dispersed when they flew to their targets and this enabled the night fighters of the German Kammhuber Line to cause casualties among each succeeding flight as they passed through the various ‘boxes’. To counter this the bomber-stream, first used for the thousand-bomber raid on Cologne in May 1942, was introduced. Instead of bombers converging on their target from their airfields separately they were gathered in one stream by giving each bomber a time and height to fly over a predetermined point. This created, by the time the Kammhuber Line was being approached, a mass of aircraft 112 km. (70 mi.) long and some 1,200 m. (4,000 ft.) deep, which, with any luck, completely overwhelmed the Kammhuber defensive box through which it flew. Air gunners had strict orders never to open fire unless attacked as a bomber was more likely to survive by evasion in the dark than by taking the offensive. If attacked, the corkscrew manoeuvre was the best tactic to employ (see Figure 2); Martin Middlebrook relates (see The Nuremberg Raid, London, 1973, p. 31) how one German night-fighter ace followed a corkscrewing Lancaster bomber for three-quarters of an hour without once being able to get into a firing position.

As the war progressed all kinds of electronic warfare devices were brought into play to confuse German radar and thus misdirect the German night-fighters scrambled to intercept the bomber-stream. ‘Spoof’ raids were also started to draw them off from the bomber-stream. These were first employed on a large scale during the air offensive against Berlin, which started in August 1943. Non-operational aircraft were assembled over the UK and flown towards the target area before, or simultaneously with, the bomber-stream. If they timed it right they turned back after the fighter defences had been committed to attacking them but before they could themselves be caught, and the main bomber-stream was able to avoid attack. ‘Spoof’ raids were also mounted by small numbers of the bomber version of the Mosquito, operational from mid-1942, which was too fast to be caught. When bombing real targets Mosquitoes often attacked in two formations, one at low level co-ordinated with the other making a shallow dive, a tactic which split the defences very effectively.

Because it employed precision bombing during the day against its targets the USAAF faced different problems in devising methods to protect its aircraft. Until long-range fighters became operational in early 1944 the bombers had to rely on their own armament and employ formations which gave maximum mutual defensive firepower. To this end the numbers of aircraft in a formation, and the compactness of the formation, increased as the war progressed. As both the B17 Fortresses and the B24 Liberators were heavily armed it was initially believed that they were capable of fighting their way to and from their targets in the Eighth USAAF's basic formation of six aircraft (see Figure 3). Four of these formations flown together, but as much as 6.4 km. (4 m.) apart, allowed plenty of manoeuvrability when bombing but proved quite inadequate for defence. So in September 1942 18-aircraft groups were introduced (see Figure 4 ) which brought the aircraft closer together and concentrated their firepower. But it was somewhat inflexible and when the formation turned it tended to cause stragglers—the death knell for any bomber. Though this was revised in December 1942 German fighters still caused heavy losses and from March 1943 the 54-aircraft combat wing formation began being used. Three 18-aircraft groups were brought together into a compact unit which was about 2,000 m. (2,200 yd.) wide and 800 m. (880 yd.) deep with 550 m. (600 yd.) between the first and last aircraft. This increased mutual fire support considerably but required new bombing techniques, including pattern bombing. The ‘tucked in’ 54-aircraft wing formation followed soon afterwards which squeezed the aircraft even closer together so that they used nearly 75% less air space. This presented a truly formidable concentration of firepower as well as a reduced target for the head-on fighter attacks that the Luftwaffe had developed. This formation continued to be used until the introduction of the long-range fighter in early 1944, and then the appearance of massed anti-aircraft batteries that defended German cities in early 1945, each of which prompted a change of formation. With fighters to accompany bombers throughout a raid, self-protection became a lower priority than maximizing the use of those with the latest electronic navigation systems which were in short supply. One of these aircraft led a squadron of twelve, with three squadrons flying together in an arrow-shaped group. Finally, in February 1945, four squadrons of nine aircraft each were flown in one group. This made them easy to protect and as each squadron flew at a different height made it difficult for the German gunners to shift fire from one squadron to another.

In the Pacific war, where air-to-air bombing was a frequent Japanese tactic, the bomber tactics of the USAAF attacking Japan with the new B29 also underwent a number of radical changes. At first the air commanders used the tried and tested tactics of day precision bombing from high altitude, but this produced disappointing results, due partly to strong winds at such a height. So, in January 1945, Maj-General LeMay was brought in with orders to mount area bombing raids with incendiaries. He achieved a startling success which, in the opinion of the US official air historians, marked him ‘as one of the very greatest of operational air commanders of the war’ ( W. Craven and J. Cate, eds., The Army Air Forces in World War II, Vol. 5, Chicago, 1958, p. 608). He achieved it by adopting a daring tactic. His bombers, packed with incendiaries, began flying lower altitude sorties at night (around 1,830 m. or 6,000 ft.), and, to increase their speed and bomb load, he had all their armament stripped except the tail gun. This tactic was first used to raid Tokyo on the night of 9/10 March. It was a calculated gamble which paid off. These ‘Fire Raids’ inflicted greater material damage on Japan than the two atomic bombs.

I. C. B. Dear

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