The Heinkel He 111 was a German aircraft designed by Siegfried and Walter Günter in the early 1930s in violation of the Treaty of Versailles. Often described as a “Wolf in sheep’s clothing”, it masqueraded as a transport aircraft, though its actual purpose was to provide the Luftwaffe with a fast medium bomber. Perhaps the best-recognised German bomber due to the distinctive, extensively glazed, bullet-shaped “greenhouse” nose of later versions, the Heinkel was the most numerous and the primary Luftwaffe bomber during the early stages of World War II. It fared well until the Battle of Britain, when its weak defensive armament, relatively low speed, and poor manoeuvrability were exposed. Nevertheless, it proved capable of sustaining heavy damage and remaining airborne. As the war progressed, the He 111 was used in a variety of roles on every front in the European Theatre. It was used as a strategic bomber during the Battle of Britain, a torpedo bomber during the Battle of the Atlantic, and a medium bomber and a transport aircraft on the Western, Eastern, Mediterranean, Middle Eastern, and North African Fronts. Although constantly upgraded, the Heinkel He 111 became obsolete during the latter part of the war. It was intended to be replaced by the Luftwaffe’s Bomber B project, but the delays and eventual cancellation of the project forced the Luftwaffe to continue using the He 111 until the end of the war. Manufacture ceased in 1944, at which point, piston-engine bomber production was largely halted in favour of fighter aircraft. With the German bomber force defunct, the He 111 was used for transport and logistics. The design of the Heinkel endured after the war in the CASA 2.111. The Spanish received a batch of He 111H-16s in 1943 along with an agreement to licence-build Spanish versions. Its airframe was produced in Spain under license by Construcciones Aeronáuticas SA. The design differed significantly in powerplant only. The Heinkel’s descendant continued in service until 1973, when it was retired.
He 111 H-2
The H variant of the He-111 series was more widely produced and saw more action during World War II than any other Heinkel variant. Owing to the uncertainty surrounding the delivery and availability of the DB 601 engines, Heinkel began tests with the 820 kW (1,100 hp) Junkers Jumo 211 powerplants. The somewhat larger size and greater weight of the Jumo 211 engines were unimportant considerations for a twin engine design, and the Jumo was used on almost all early-war bomber designs. When the Jumo was fitted to the P model it became the He 111 H.
The He 111 H-1 was fitted with a standard set of three 7.92 mm MG 15s and eight SC 250 250 kg or 32 SC 50 50 kg bombs. The same armament was used in the H-2 which started production in August 1939. The P-series was gradually replaced on the eve of war with the new the H-2, powered by improved Jumo 211 A-3 engines of 820 kW (1,100 hp). A count on 2 September 1939 revealed that the Luftwaffe had a total of 787 He 111s in service, with 705 combat ready, including 400 H-1 and H-2s that had been produced in a mere four months.
He 111 H-3
Production of the H-3, powered by the 895 kW (1,200 hp) Jumo 211 D-1, began in October 1939. The experiences during the Polish Campaign led to an increase in defensive armament. MG 17s were fitted whenever possible and the number of machine guns was increased to seven. Normally one MG 17 would be installed in the nose, one in the ventral position, dorsal position and one in each waist window position. The two waist positions received an additional MG 15 or 17. On some Heinkels a permanent belt-fed MG 17 was installed in the tail.
After the Battle of Britain, smaller scale production of the H-4s began. The H-4 was virtually identical to the He 111 P-4 with the DB 600s swapped for the Jumo 211D-1s. This variant also differed from the H-3 in that it could either carry 2,000 kg (4,410 lb) of bombs internally or mount one or two external racks to carry one 1,800 kg (3,970 lb) or two 1,000 kg (2,210 lb) bombs. As these external racks blocked the internal bomb bay doors, a combination of internal and external storage was not possible. A PVR 1006L bomb rack was fitted externally and a 835 L (221 US gal) tank added. The PVR 1006L was capable of carrying a SC 1000 1,000 kg (2,210 lb) bomb. Some H-4s had their PVC racks modified to drop torpedoes. Later modifications enabled the PVC 1006 to carry a 2,500 kg (5,510 lb) “Max” bomb. But 1,000 kg (2,200 lb) “Hermann” or 1,800 kg (3,970 lb) “Satans” were used more widely. The H-5 series followed in February 1941, with heavier defensive armament. Like the H-4, it retained a PVC 1006 L bomb rack to enable it to carry heavy bombs under the fuselage. The first ten He 111 H-5s were pathfinders, and selected for special missions. The aircraft sometimes carried 25 kg flashlight bombs which acted as flares. The H-5 could also carry heavy fire bombs, either heavy containers or smaller incendiary devices attached to parachutes. The H-5 also carried LM A and LM B aerial mines for anti-shipping operations. After the 80th production aircraft, the PVC 1006 L bomb rack was removed and replaced with a heavy-duty ETC 2000 rack, enabling the H-5 to carry the SC 2500 “Max” bomb, on the external ETC 2000 rack, which enabled it to support the 5,000 lb (2,300 kg) bomb. Some H-3 and H-4s were equipped with barrage balloon cable-cutting equipment in the shape of cutter installations forward of the engines and cockpit. They were designated H-8, but later named H8/R2. These aircraft were difficult to fly and the production stopped.
He 111 H-6
The H-6 initiated some overall improvements in design. The Jumo 211 F-1 engine of 1,007 kW (1,350 hp) increased its speed while the defensive armament was upgraded with one 20 mm MG FF cannon in the nose position, one MG 15 in the ventral turret, and in each of the fuselage side windows (optional). Some H-6 variants carried tail-mounted MG 17 defensive armament. The performance of the H-6 was much improved. The climb rate was higher and the machine could reach a slightly higher ceiling of 8,500 m (27,200 ft). When heavy bomb loads were added, this ceiling was reduced to 6,500 m (20,800 ft). The weight of the H-6 increased to 14,000 kg (30,600 lb). Some H-6s received Jumo 211F-2s which improved a low-level speed of 226 mph (365 km/h). At an altitude of 6,000 m (19,200 ft) the maximum speed was 270 mph (435 km/h). If heavy external loads were added, the speed was reduced by 21.75 mph (35 km/h) Other designs of the mid-H series included the He 111 H-7 and H-8. The airframes were to be rebuilds of the H-3/H-5 variant. Both were designed as night bombers and were to have two Jumo 211F-1s installed. The intention was for the H-8 to be fitted with cable-cutting equipment and barrage ballon deflectors on the leading edge of the wings. The H-7 was never built. The H-9 was intended as a trainer with dual control columns. The airframe was a H-1 variant rebuild.
The powerplants consisted of two JumoA-1s or D-1s. The H-10 was also designated to trainer duties. Rebuilt from an H-2 or H-3 airframe, it was installed with full defensive armament including 13 mm (.51 in) MG 131 and 7.92 mm (.312 in) MG 81Z machine guns. It was to be powered by two Jumo 211A-1s, D-1s or F-2s.
He 111 H-11
In the summer of 1942, the H-11, based on the H-3 was introduced. With the H-11, the Luftwaffe had at its disposal a powerful medium bomber with heavier armour and revised defensive armament. The drum-fed 7.92 mm (.312 in) MG 15 was replaced with a belt-fed 13 mm (.51 in) MG 131 in the now fully enclosed dorsal position (B-Stand); the gunner in the latter was now protected with armoured glass. The single MG 15 in the ventral C-Stand or Bola was also replaced, with a belt-fed 7.92 mm (.312 in) MG 81Z with much higher rate of fire. The beam positions originally retained the single MG 15s, but the H-11/R1 replaced these with twin MG 81Z as well; this latter arrangement was standardized in November 1942. The port internal ESAC bomb racks could be removed, and an 835 L (221 US gal) fuel tanks installed in its place. Many H-11s were equipped with a new PVC rack under the fuselage, which carried five 250 kg (550 lb) bombs. Additional armour plating was fitted around crew spaces, some of it on the lower fuselage and could be jettisoned in an emergency. Engines were two 1,000 kW (1,340 hp) Junkers Jumo 211F-2, allowing this variant to carry a 2,000 kg (4,410 lb) payload to a range of 2,340 km (1,450 mi). Heinkel built 230 new aircraft of this type and converted 100 H-3s to H-11s by the summer of 1943.
He 111Z “Zwilling”
The He 111Z Zwilling was a design that entailed the merging of two He 111s. The design was originally conceived to tow the
Messerschmitt Me 321 glider. Initially, four He 111 H-6s were modified. This resulted in a twin-fuselage, five-engine aircraft. They were tested at Rechlin, and the pilots rated them highly. A batch of 10 were produced and five were built from existing H-6s. The machines were joined by a centre wing formed by two sections 6.15 m in length. The powerplants were five Jumo 211F engines at 1,000 kW (1,340 hp) each. Total fuel capacity was 8,570 L (2,260 US
gal). This was increased with the addition of four 600 L (160 US gal) drop tanks. It could tow a Gotha Go 242 glider or Me 321 for up to10 hours at cruising speed. It could also remain airborne if the three centralised powerplants failed. The He 111 Z-2s and Z-3s were also planned as heavy bombers carrying 1,800 kg (3,970 lb) of bombs and having a range of 4,000 km (2,500 mi). The ETC extensions allowed for a further four 600 L (160 US gal) drop tanks to be installed. The He 111 Z-2 could carry four Henschel Hs 293 anti-shipping guided missile, which were guided by the FuG 203b Kehl III missile control equipment. With this load the He 111Z had a range of 1,094 km (680 mi) and a speed of 314 km/h (195 mph). Its maximum bombload was 7,200 kg (15,870 lb). To increase power the five Jumo 211F-2 powerplants were to be fitted with Hirth TK 11 superchargers. The armament was the same as the H-6 with the addition of one 20 mm MG 151/20 in a rotating gun-mount of the centre section. The variant did not display any convincing (stable) flight performance. The layout of the He 111Z had the pilot and his controls in the port fuselage only. Only the controls themselves and essential equipment remaining in the starboard section. The aircraft had a crew of seven; a pilot, first mechanic, radio operator and gunner in the port fuselage, and the observer, second mechanic and gunner in the starboard fuselage. The Z-3 was to be a reconnaissance version and was to have additional fuel tanks increasing its range to 6,000 km (3,730 mi). Production was due to take place in 1944, just as bomber production was being abandoned. The long-range variant designs failed to come to fruition. The He 111Z was to have been used in an invasion of Malta in 1942 and as part of an airborne assault on the Soviet cities Astrakhan and Baku in the Caucasus in the same year. During the Battle of Stalingrad their use was cancelled due to insufficient airfield capacity. Later in 1943 it helped evacuate German equipment and personnel from the Caucasus region and during the Allied invasion of Sicily attempted to deliver reinforcements to the island. During operations, the He 111Z did not have enough power to lift a fully loaded Me 321. The He 111s in RATO (rocket assisted takeoff) units were supplemented by rocket pods. Two were mounted beneath each fuselage and one underneath each wing. This added 500 kg (1,100 lb) in weight, but gave additional thrust to the engines. The pods were then released by parachute after takeoff. The He 111Z’s operational history was minimal. One such machine was caught by RAF fighter aircraft over France on 14 March 1944. The He 111Z was towing a Gotha Go 242, and was shot down. Eight were shot down or destroyed on the ground in 1944.
