The Heinkel He 111 was a German medium bomber designed by Siegfried and Walter Günter in the early 1930s in violation of the Treaty of Versailles. The Heinkel became the most numerous and primary Luftwaffe bomber during the early stages of World War II. It is perhaps the most famous symbol of the German bomber force (Kampfwaffe) due its distinctive "Greenhouse" nose.
The He 111 took on the mantle of "workhorse", and was used in a variety of roles on every front in the European Theatre throughout the war. It was used as a strategic bomber during the Battle of Britain, a torpedo bomber during the Battle of the Atlantic, a medium bomber and a transport aircraft on the Western Front, Eastern Front and Mediterranean and North African Fronts. It became obsolete, but the failure to design and produce a successor meant the He 111 continued to be produced until 1944, when piston-engined bomber production was largely halted, in favour of fighter aircraft. The design of the Heinkel endured after the war in the CASA 2.111. 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.
In the early 1930s, Ernst Heinkel decided to build the world's fastest passenger plane, a lofty goal met by more than a little skepticism by the German aircraft industry and its newly evolving political leadership. Heinkel entrusted the development to the Günter brothers, fairly new to the company and untested.
The aircraft was superior to the already fast Lockheed 9 Orion that their design was competing against. The first example of their soon-to-be-famous Heinkel He 70 Blitz (“Lightning”) rolled off the line in 1932 and immediately started breaking records. In its normal four-passenger version, its speed almost reach 200 mph (320 km/h), even though it was powered by only a single 600 hp (447 kW) BMW V1 engine. The elliptical wing, which the Günther brothers had already used in the Bäumer Sausewind sports plane before they joined Heinkel, became a feature in many subsequent designs the brothers developed. The design immediately garnered the interest of the Luftwaffe, which was looking for medium bombers for military service.
The future Heinkel He 111 was a more powerful twin-engine version of the Blitz, producing an aircraft that had many of the Blitz's features, including its elliptical inverted gull wing, small rounded control surfaces, and BMW engines. With location of the engines the only notable change in appearance, the new He 111 design was often called the Doppel-Blitz (“Double Lightning”).
The first prototype, He 111 V1 (W.Nr. 713, D-ADAP), first flew from Rostock-Marienehe on 24 February 1935. It was followed by the civilian-equipped V2 and V4 in May 1935. The V2 (W.Nr. 715, D-ALIX) used the bomb bay as a four-seat "smoking compartment", with another six seats behind it in the rear fuselage. V2 entered service with Lufthansa in 1936, along with five newly-built versions known as the He 111 C.
The design was only masquerading as an airliner. The aircraft was intended to be a bomber as the Luftwaffe began rearmament.
The initial reports from the test pilot, Gerhard Nitschke, were favourable. It flight performance and handling were impressive although it dropped its wing in the stall. As a result the passenger variants had their wings reduced from 25 to 23 metres. The military aircraft, the V1, V3 and V5 spanned just 22.6 metres.
The first prototypes were underpowered, as they were equipped with 578 hp BMW VI 6.0 six-cylinder in-line engines. This was eventually increased to 999 hp with the fitting of the DB (Daimler-Benz) 600 engines into the V5, which became the prototype of the "B" series.
Only ten He 111 A-0 models based on the V3 were built, but they proved to be underpowered and were eventually sold to China. The type had been lengthened by 1.2 metres due to the added 7.92 mm MG 15 machine gun in the nose. Another gun position was installed on top of the fuselage, and another in a ventral position, which could retract. The bomb compartment was divided into two compartments and could carry 1,500 lbs of bombs. The problem with these additions was that the weight of the aircraft reached 8,200Kg. The He 111's performance was seriously reduced; in particular, the BMW VI 6.0 Z engines were not now powerful enough. The increased length also altered the 111's aerodynamic strengths and reduced its excellent handling on takeoffs and landings. The crews found the aircraft difficult to fly, and its top speed was reduced significantly. Production was shut down after the pilots reports reached the RLM. However, a Chinese delegation was visiting Germany and they considered the He 111 A-0 fit for their needs and purchased seven machines.
The first He 111B made its maiden flight in the autumn of 1936. After improvements, the Reichsluftfahrtministerium (RLM—Air Ministry) ordered 300 He 111B-1s; the first were delivered in January 1937. The B-2 variant had its engines upgraded to the supercharged 850 hp DB 600C, or in some cases, the 925 hp 600G. The B-2 began to roll off the production lines at the Heinkel works in Oranienburg in 1937. In late 1937, the D-1 series entered production. However, the DB600Ga engine with 1,074 hp planned for this variant was instead allocated to the Bf 109 and Bf 110 production lines. Heinkel then opted to use Jumo engines, and the He 111 V6 was tested with Jumo 210 G engines, but was vastly underpowered. However, the improved 999 hp Jumo 211 A-1 powerplant prompted the cancellation of the D series altogether and concentration on the design of the E series.
The E-1s came off the production line in February 1938, in time for a number of these aircraft to serve in the Condor Legion during the Spanish Civil War in March 1938. In a way, the positive performance influenced later variants. The Luftwaffe believed that because the E variant could outrun enemy fighters, there was no need to upgrade the defensive weaponry, which would prove a mistake from the Battle of Britain onward. The fuselage bomb bay used four bomb racks, in later versions eight modular standard bomb racks designed to carry one SC 250, 250 kg bomb or four SC50, 50 kg bombs each in nose up orientation (which resulted in the bombs doing a flip as they were dropped out of the aircraft). These modular standard bomb racks were a common feature on the first generation of Luftwaffe bombers (including the Junkers Ju 52), but it turned out that they limited the ordnance selection to bombs of only two sizes. Since they had to be built strongly enough to carry heavy bombs without contributing to the structural integrity of the aircraft, these racks were abandoned in later designs. The E-3 series was produced with only a few modifications, such as external bomb racks. The E-4 variant was fitted with external bomb racks also and the empty bombay space was filled with a 835 litre tank for aviation fuel and a further 115 litre oil tank. This increased the loaded weight to nearly 11 tons, but increased its range to 1,800 km (1,125 miles). The modifications allowed the He 111 to perform both long and short range missions.
The new design was powered by the DB 601 Ba engine with 1,175 PS and reduced the length of the aircraft by 1.1 metres. It was designated as P-0, and the first production lines reached their units in the autumn of 1938. In May 1939 the P-1 and P-2 went into service with improved radio equipment. The P-2, like the later P-4 was given stronger armour and two MG 15 machine guns on either side of the fuselage and two external bomb racks.
Many of the He 111 Ps served during the Polish Campaign. With the Junkers Ju 88 experiencing technical difficulties, the He 111 and the Dornier Do 17 formed the backbone of the Kampfwaffe. On 1 September 1939, Luftwaffe records indicate the Heinkel strength at 705 (along with 533 Dorniers).
The P-6 variant was the last production model of the He 111 P series. In 1940, the RLM abandoned further production of the P series in favour of the H versions, mostly because the P-series' Daimler-Benz engines were sorely needed for Messerschmitt Bf 109 and Bf 110 fighter production. The remaining P-6s were redesignated P-6/R2s and used as heavy glider tugs.
The H variant of the He 111 series was more widely produced and saw more action during the Second World War than any other Heinkel variant.
Owing to the uncertainty surrounding the delivery and availability of the DB 601 engines, Heinkel began tests with the 1,100 hp (820 kW) 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 P-series was gradually replaced on the eve of war with the new the H-2, powered by Jumo 211 A-3 engines. 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. Production of the H-3, powered by the 1,200 hp Jumo 211 D-1, began in November 1939. After the Battle of Britain, smaller scale production of the H-4s began. This variant differed from the H-3 in that could either carry 2.000 kg of bombs internally or mount one or two external racks to carry one 1.800 kg or two 1.000 kg bombs. As these external racks blocked the internal bomb bay doors, a combination of internal and external storage was not possible. The H-5 series followed in February 1941, with heavier defensive armament. 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.The H-6 initiated some all around improvements in design. The Jumo 211 F-1 engine of 1,350 hp increased its speed while the defensive armament was upgraded with one MG FF 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. With the H-11, the Luftwaffe had at its disposal a powerful medium bomber with heavier armour and defensive armament.
One of the most interesting variants was a glider tug, the He 111 Z, standing for Zwilling or twin. It was built from two 111 H-6s joined together with a connecting wing and a fifth engine and used to tow the giant Messerschmitt Me 321 or two Gotha Go 242 gliders. Ten He 111 Zs were built, and all served until destroyed.
At 14,000 kg take-off weight (carrying 2,000 kg of bombs internally), the He 111H achieved a top speed of 405 km/h at 6 km, improving to 435 km/h without the bomb load and at 50% fuel load. Still, this was considerably slower than the newer Junkers Ju 88 which entered service in 1940, so the He 111 was gradually withdrawn from the bomber role. The He 111 became a jack-of-all-trades as the war progressed, carrying out missions not even imagined when the war started.
Nevertheless, the He 111 had to be kept in production until 1944 because the RLM failed to provide a successor: the He 177 Greif heavy bomber was plagued by engine problems, and the Bomber B program was eventually abandoned. The vast majority of the 7,300 He 111s produced would be the H models, largely identical to the first H introduced in 1939.
Only three original German built He 111's survivors are on display or stored in museums around the world (not including major sections). Of the three complete German built Heinkels, one E-3 series (Wk Nr 2940) with the 'conventional' cockpit is on display at Museo del Aire, Madrid, Spain, having served in the Condor Legion. The Second, a mostly complete He 111P-2 (Wk Nr 1526), is on display at the Norwegian Air Force Museum at Gardermoen. The third, a H-20, Wk Nr 701152, is on display at the RAF Museum Hendon, London.
In 2005 another He 111 was salvaged from a Norwegian lake and has since been moved to Germany for restoration, and may be the most complete wartime He 111 to date. Unrelated to this effort are efforts by several organizations to restore one to flyable condition.
Approximately 14 Spanish licensed built CASA 2.111s survive today in various conditions on display or storage. One modified Spanish 2.111D served as a transport for Spanish VIPs, including General Francisco Franco, before being purchased in England by the Commemorative Air Force in 1977. It remained the last He 111 in flyable condition until July 10, 2003, when it was destroyed in a fatal crash landing. The aircraft was attempting a landing at the Cheyenne Municipal Airport, near Cheyenne, Wyoming, while en route from Midland, Texas to an air show in Missoula, Montana. Eyewitness reports indicate the aircraft lost power to one engine on final approach and ploughed through a chain link fence before colliding with a school bus washing building under construction. Killed were CAF pilot Neil R. Stamp and co-pilot Charles S. Bates.