With its defeat in World War I, the leaders of Germany signed the Treaty of Versailles which formally ended the conflict. Though a far-reaching agreement, one section of the treaty specifically forbade Germany from constructing and operating an air force. Due to this restriction, when Germany commenced rearmament in the early 1930s, aircraft development occurred in secrecy or proceeded under the guise of civilian use. Around this time, Ernst Heinkel commenced an initiative to design and build a high-speed passenger plane. To design this aircraft, he hired Siegfried and Walter Günter. The result of the Günters' efforts was the Heinkel He 70 Blitz which began production in 1932. A successful aircraft, the He 70 featured an elliptical inverted gull wing and a BMW VI engine.
Impressed with the He 70, the Luftfahrtkommissariat, which sought a new transport aircraft that could be converted to a bomber in wartime, contacted Heinkel. Responding to this inquiry, Heinkel began work to enlarge the aircraft to meet the requested specifications and to compete with new twin-engine aircraft such as the Dornier Do 17. Preserving the key features of the He 70, including the wing shape and BMW engines, the new design became known as the Doppel-Blitz ("Double Blitz"). Work on the prototype pushed forward and it first took to the skies on February 24, 1935, with Gerhard Nitschke at the controls. Competing with the Junkers Ju 86, the new Heinkel He 111 compared favorably and a government contract was issued.
Design & Variants
Early variants of the He 111 utilized a traditional stepped cockpit with separate windscreens for the pilot and copilot. Military variants of the aircraft, which began production in 1936, saw the inclusion of dorsal and ventral gun positions, a bomb bay for 1,500 lbs. of bombs, and a longer fuselage. The addition of this equipment adversely affected the He 111's performance as the BMW VI engines did not produce sufficient power to offset the additional weight. As a result, the He 111B was developed in the summer of 1936. This upgrade saw more powerful DB 600C engines with variable pitch airscrews installed as well as additions to the aircraft's defensive armament. Pleased with the improved performance, the Luftwaffe ordered 300 He 111Bs and deliveries commenced in January 1937.
Subsequent improvements produced the D-, E-, and F-variants. One of the most notable changes during this period was the elimination of the elliptical wing in favor of a more-easily produced one featuring straight leading and trailing edges. The He 111J variant saw the aircraft tested as a torpedo bomber for the Kriegsmarine though the concept was later dropped. The most visible change to the type came in early 1938 with the introduction of the He 111P. This saw the entire forward part of the aircraft altered as the stepped cockpit was removed in favor of a bullet-shaped, glazed nose. In addition, improvements were made to the power plants, armament, and other equipment.
In 1939, the H-variant entered production. The most widely produced of any He 111 model, the H-variant began entering service on the eve of World War II. Possessing a heavier bomb load and greater defensive armament than its predecessors, the He 111H also included enhanced armor and more powerful engines. The H-variant remained in production into 1944 as the Luftwaffe's follow-on bomber projects, such as the He 177 and Bomber B, failed to yield an acceptable or reliable design. In 1941, a final, mutated variant of the He 111 commenced testing. The He 111Z Zwilling saw the merging of two He 111s into one large, twin-fuselage aircraft powered by five engines. Intended as a glider tug and transport, the He 111Z was produced in limited numbers.
In February 1937, a group of four He 111Bs arrived in Spain for service in the German Condor Legion. Ostensibly a German volunteer unit supporting Francisco Franco's Nationalist forces, it served as a training ground for Luftwaffe pilots and for evaluating new aircraft. Making their combat debut on March 9, the He 111s attacked Republican airfields during the Battle of Guadalajara. Proving more effective than the Ju 86 and the Do 17, the type soon appeared in larger numbers over Spain. Experience with the He 111 in this conflict allowed designers at Heinkel to further refine and improve the aircraft. With the beginning of World War II on September 1, 1939, He 111s formed the backbone of the Luftwaffe's bombing assault on Poland. Though performing well, the campaign against the Poles revealed that the aircraft's defensive armament required enhancement.
In the early months of 1940, He 111s conducted raids against British shipping and naval targets in the North Sea before supporting the invasions of Denmark and Norway. On May 10, Luftwaffe He 111s aided ground forces as they opened the campaign in the Low Countries and France. Taking part in the Rotterdam Blitz four days later, the type continued to strike both strategic and tactical targets as the Allies retreated. At the end of the month, He 111s mounted raids against the British as they conducted the Dunkirk Evacuation. With the fall of France, the Luftwaffe began preparing for the Battle of Britain. Concentrating along the English Channel, He 111 units were joined by those flying the Do 17 and Junkers Ju 88. Commencing in July, the assault on Britain saw the He 111 encounter fierce resistance from Royal Air Force Hawker Hurricanes and Supermarine Spitfires. The early phases of the battle showed a need for the bomber to have a fighter escort and revealed a vulnerability to head-on attacks due to the He 111's glazed nose. In addition, repeated engagements with British fighters showed that the defensive armament was still inadequate.
In September, the Luftwaffe switched to targeting British cities. Though not designed as a strategic bomber, the He 111 proved capable in this role. Fitted with Knickebein and other electronic aids, the type was able to bomb blind and maintained pressure on the British through the winter and spring of 1941. Elsewhere, the He 111 saw action during the campaigns in the Balkans and the invasion of Crete. Other units were sent to North Africa to support the operations of the Italians and the German Afrika Korps. With the German invasion of the Soviet Union in June 1941, He 111 units on the Eastern Front were initially asked to provide tactical support for the Wehrmacht. This expanded to striking the Soviet rail network and then to strategic bombing.
Though offensive action formed the core of the He 111's role on the Eastern Front, it also was pressed into duty on several occasions as a transport. It earned distinction in this role during by evacuating wounded from the Demyansk Pocket and later in re-supplying German forces during the Battle of Stalingrad. By the spring of 1943, overall He 111 operational numbers began to decline as other types, such as the Ju 88, assumed more of the load. In addition, increasing Allied air superiority hampered offensive bombing operations. During the war's later years, the He 111 continued to mount raids against Soviet shipping in the Black Sea with the assistance of FuG 200 Hohentwiel anti-shipping radar.
In the west, He 111s were tasked with delivering V-1 flying bombs to Britain in late 1944. With the Axis position collapsing late in the war, He 111s supported numerous evacuations as German forces withdrew. The He 111's final missions of the war came as German forces attempted to halt the Soviet drive on Berlin in 1945. With the surrender of Germany in May, the He 111's service life with the Luftwaffe came to an end. The type continued to be used by Spain until 1958. Additional license-built aircraft, constructed in Spain as the CASA 2.111, remained in service until 1973.
Heinkel He 111 H-6 Specifications
- Length: 53 ft., 9.5 in.
- Wingspan: 74 ft., 2 in.
- Height: 13 ft., 1.5 in.
- Wing Area: 942.92 sq. ft.
- Empty Weight: 19,136 lbs.
- Loaded Weight: 26,500 lbs.
- Maximum Takeoff Weight: 30,864 lbs.
- Crew: 5
- Maximum Speed: 273 mph
- Range: 1,429 miles
- Rate of Climb: 850 ft./min.
- Service Ceiling: 21,330 ft.
- Power Plant: 2 × Jumo 211F-1 or 211F-2 liquid-cooled inverted V-12
- 7 × 7.92 mm MG 15 or MG 81 machine guns, (2 in the nose, 1 in the dorsal, 2 on the side, 2 ventral. These may have been replaced by 1 × 20 mm MG FF cannon (nose mount or forward ventral position) or 1 × 13 mm MG 131 machine gun (mounted dorsal and/or ventral rear positions)
- Bombs: 4,400 lb. in internal bomb bay