Science Fair Project Encyclopedia
Heinkel He 111
|Heinkel He 111|
|First Flight||February, 1935|
|Manufacturer||Ernst Heinkel Flugzeugwerke GmbH|
|Dimensions (He 111K Mk.V)|
|Length||16.6 m||54' 6"|
|Wingspan||22.6 m||74' 3"|
|Height||4.2 m||13' 9"|
|Wing area||87.5 m²||942 ft²|
|Empty||5,850 kg||12,900 lb|
|Loaded||11,300 kg||24,900 lb|
|Maximum takeoff||12,400 kg||27,400 lb|
|Engine||2 Daimler-Benz DB 601A|
|Power (each)||1,540 kW||1,150 hp|
|Maximum speed||440 km/h||274 mph|
|Combat range||2,150 km||1,336 miles|
|Ferry range||3,440 km||2,140 miles|
|Service ceiling||7,350 m||24,100 ft|
|Rate of climb||270 m/min||890 ft/min|
|Wing loading||129 kg/m²||26.4 lb/ft²|
|Power/Mass||0.27 kW/kg||0.092 hp/lb|
|Bombs||2,000 kg||4,410 lb|
The Heinkel He 111 was the primary Luftwaffe medium bomber during the early stages of World War II, and is perhaps the most obvious symbol of the German side of the Battle of Britain. Developed from a pre-war airliner design, the He 111 was phased out of front line service in 1942, but remained in production until the end of the war.
In the early 1930s Ernst Heinkel decided to build the world's fastest passenger plane, a lofty goal met with more than a little scepticism by the German aircraft industry and its newly evolving political leadership. To make matters worse he entrusted the development to the Günther brothers, fairly new to the company and basically untested.
To everyone's surprise they delivered on the promise, delivering a design superior to the already fast Lockheed 9 Orion they based their work on. The first example of their soon-to-be-famous Heinkel He 70 Blitz rolled off the line in 1932 and immediately started breaking record after record. In its normal 4 passenger version it cruised at almost 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 designs the brothers developed subsequently.
It was only a matter of time before they turned their attention to developing a larger and more powerful twin-engine version of the Blitz, producing a plane that had many of the Blitz's features – including its elliptical wing with a reverse gull-wing bend, small rounded control surfaces, and BMW engines. With the engines moved off the nose being the only notable change in looks, their new He 111 design was often called the Doppel-Blitz (double-Blitz).
The design immediately garnered the interest of the Luftwaffe brass, who were looking for any design that could be pressed into military service. They tendered a contract for several prototype bombers, to be delivered as airliners to keep the work secret.
He 111V1 was completed as a bomber prototype and kept secret. It first flew in February 1935, and was followed quickly by the civilian-equipped V2. V2 had a smaller wing, and 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 111C.
V3 was also completed as a bomber prototype. It supplanted the main bomb bay with smaller bays in the inner wings, and was armed with three MG15 machine guns for defence. The added weight slowed the plane considerably, which now cruised at a measly 170 mph (275 km/h).
Ten He 111A-0 models based on the V3 were built, but they proved to be underpowered and were eventually sold to China.
In early 1936, the V3 was fitted with 950 hp (708 kW) Daimler-Benz DB 600 Aa engines. Performance jumped to about 225 mph (360 km/h), and the Luftwaffe placed orders for over 300 He 111B models. Some of these planes were sent to Spain to serve with the Condor Legion, where they proved to be able to out fly the majority of fighters sent to intercept them, and it appeared that the light three-gun armament was more than enough to handle the ones that managed to catch them. This would lead the Luftwaffe into a false sense of security, as the days of the bomber being faster than the fighters would be short-lived and the woeful armament would soon prove to be deadly.
An interesting design note is the fuselage bomb bay. It was designed to carry 8 SC250, 250 kg bombs nose up in 8 cells. This resulted in the bomb doing a flip as it was dropped out of the aircraft, and supposedly increased accuracy. What it did do was severely limit what the 111 could carry internally. To carry larger and heavier bombs, it was forced to use external weapon mounts, which slowed the bomber with increased drag.
The design quickly ran though a series of minor design versions to fix one sort of problem or another. One of the more obvious changes started with the He 111F models, which moved from the elliptical wing to one with straight leading and trailing edges, which was easier to build.
The DB engine was always a problem because the German engine industry couldn't produce enough of them, but as the best engine of its day it was used in practically every design. Eventually the RLM (the German Air Ministry) decided that all of the DB engines would go to Messerschmitt for use in the Bf 109 and Bf 110. Many promising designs were cancelled due to this decision, while most other designs were forced to switch engines. The result for the He 111 was a slew of minor versions with all sorts of engine installations - basically whatever they could find.
One of these runs was the He 111P, which mounted the updated Daimler-Benz DB 601 and a newly designed nose section that replaced the 'stepped' cockpit with the now-famous glazed 'dome' over the front of the plane. These improvements allowed it to reach almost 250 mph (400 km/h). Several hundred of these were built in 1938, and saw action over Poland.
It was at this point that the new 1,100 hp (820 kW) Junkers Jumo 211 engine started deliveries. Although somewhat larger and heavier than the DB 601, these 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 111H, the most produced version of the design by far. The main versions in the early stages of the war were the H-5, which included additional guns in the rear side windows, and the similar H-6, which could optionally carry torpedoes (although they rarely did so). Both replaced the earlier versions in-wing bomb bays with additional fuel tanks for better range.
The He 111 became a jack-of-all-trades as the war progressed, carrying out missions not even imagined even when the war started. One of the most interesting was as a glider tug, the He 111Z, standing for Zwilling or twin. It was built from two 111H-6's 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 111Zs were built, and all served until destroyed one way or another.
Even with an upgraded Jumo of 1,300 hp (969 kW) the plane was now so overburdened with equipment that it could rarely reach even 220 mph (350 km/h). That meant it had neither the speed nor the guns needed to put up a fight with the modern RAF fighters it would meet over England, let alone the cannon-armed planes a year later. Nevertheless, the He 111 was kept in production until 1944 because the RLM continually dropped the ball on replacing it: the He 177 Greif was a disaster, and the entire Bomber B program was eventually abandoned. The vast majority of the 7,300 He 111's produced would be the H models, largely identical to the first H introduced in 1939.
The Spanish company CASA also produced a number of He 111s for Spain's own use. These models were designed as the 2.111, and served Spain until 1965. One of these, a 2.111D, served as a transport for Spanish VIPs before being purchased 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 contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details