Bf 109E-4 Specifications
Crew: Pilot only
Powerplant: One 1,150 hp Daimler Benz DB601 twelve-cylinder liquid-cooled engine
Span: 32 ft 4½ in (9.87 m)
Length: 28 ft 8 in (8.74 m)
Max Speed: 357 mph (575 km/h) at 12,300 ft (3,749 m)
Armament: Two synchronized 7.92 mm (.312 in) MG 17 machine guns mounted on top of the engine cowling, firing through the propeller arc and two 20 mm MG-FF/M cannons mounted in the wings
Image: Messerschmitt Bf 109E-3 (W.Nr. 972 “Yellow 9”) of 9./JG 54 in France, 9 September 1940
Introduction
The Messerschmitt Bf 109—often informally referred to as the Me 109—was a German single-seat fighter that formed the backbone of the Luftwaffe’s Jagdwaffe throughout the Second World War. Compact, heavily armed and built around a powerful liquid-cooled engine, it became one of the most important and widely produced combat aircraft in aviation history.
Designed by Willy Messerschmitt and Robert Lusser at Bayerische Flugzeugwerke, the Bf 109 was developed in response to tactical requirements issued by the Reichsluftfahrtministerium on 6 July 1933. The new fighter was intended to replace obsolete biplanes such as the Arado Ar 64 and Heinkel He 51 and had to combine high speed, rapid climb, adequate endurance and effective armament in an aircraft that could be operated by an average frontline pilot from a typical German airfield.
Messerschmitt pursued a lightweight, streamlined design using all-metal stressed-skin construction, a fully enclosed cockpit, retractable undercarriage and a cantilever low-wing layout. Many of these features had already appeared in the company’s successful Bf 108 Taifun touring aircraft and were incorporated into the new fighter.
Development and Design
The Bf 109’s fuselage was constructed as a light-alloy monocoque in two halves joined along the centreline. Its narrow-track undercarriage was attached to the fuselage and retracted outwards into the wings. This arrangement simplified wing construction and allowed the wings to be removed without disturbing the landing gear, although it also contributed to difficult ground handling and numerous take-off and landing accidents throughout the aircraft’s service life.
Messerschmitt intended the fighter to use one of the new inverted-V12 engines being developed by Junkers and Daimler-Benz. The 680 hp Junkers Jumo 210 was selected because it was at a more advanced stage than the more powerful Daimler-Benz DB 600, but delays in delivering the Jumo forced the first prototype to use a British engine.
The Bf 109 V1 was therefore powered by a 695 hp Rolls-Royce Kestrel VI. Messerschmitt’s senior test pilot, Hans-Dietrich “Bubi” Knoetzsch, made the aircraft’s maiden flight from Augsburg-Haunstetten airfield on 28 May 1935.
Following initial factory trials, the prototype was sent to the Erprobungsstelle at Rechlin for official evaluation. It proved faster and more manoeuvrable than its principal rival, the Heinkel He 112 V1, although pilots expressed reservations about its confined cockpit, high wing loading and narrow undercarriage.
The Jumo 210A-powered Bf 109 V2 flew in October 1935 and joined the trials programme early the following year. It was armed with two synchronised 7.92 mm MG 17 machine guns mounted in the upper fuselage.
The Bf 109 V3 flew in June 1936 and incorporated provision for an engine-mounted 20 mm cannon firing through the propeller hub. Later that year, both Messerschmitt and Heinkel received contracts to produce ten pre-production aircraft for further evaluation.
During final trials at Travemünde, the Bf 109 demonstrated superior speed and climbing performance and performed an impressive series of demanding aerobatic manoeuvres. The aircraft emerged as the clear winner of the competition and was selected as the Luftwaffe’s new standard fighter.
Early Development
Production-standard Bf 109B-1 fighters began entering Luftwaffe service in February 1937. Five months later, the type made its combat debut with the Condor Legion during the Spanish Civil War, giving German pilots and commanders invaluable experience in modern fighter operations.
The early Bf 109B, C and D variants were powered by versions of the Junkers Jumo 210. Their armament gradually increased as the Luftwaffe sought greater firepower.
The Bf 109B carried two fuselage-mounted MG 17 machine guns. Attempts were made to install an additional weapon firing through the propeller hub, but the engine-mounted cannon arrangement proved unreliable.
The Bf 109C introduced two additional MG 17 machine guns in the wings, while the Bf 109D retained four-machine-gun armament. Shortages of suitable Daimler-Benz engines meant that these aircraft continued to use Jumo powerplants.
By 19 September 1938, the Luftwaffe had 583 Bf 109B, C and D variants on strength. The introduction of the more capable Bf 109E was delayed because Daimler-Benz engine production initially prioritised bomber requirements, particularly those of the Heinkel He 111.
The Bf 109E (“Emil”)
The arrival of the fuel-injected Daimler-Benz DB 601A transformed the Bf 109 into a far more capable fighter. Rated at approximately 1,175 hp for take-off, the new engine provided excellent acceleration, climbing performance and the ability to maintain fuel flow during negative-G manoeuvres.
The Bf 109E-1 entered series production in December 1938. Its armament consisted of two MG 17 machine guns in the upper fuselage and two more in the wings. The fuselage guns carried 1,000 rounds each, while the wing-mounted guns carried 500 rounds apiece.
The aircraft was equipped with a Revi C/12C reflector gunsight and a FuG 7 radio with a range of approximately 40 miles. Its higher wing loading increased both its turning circle and stall speed, making the Emil a demanding aircraft that rewarded experienced pilots.
The Bf 109E-3 began entering production in early 1939. Its two wing-mounted machine guns were replaced by 20 mm MG FF cannon, each carrying 60 rounds. Although the limited ammunition supply allowed only brief firing opportunities, the cannon gave the aircraft significantly greater destructive power than rifle-calibre machine guns alone.
The later Bf 109E-4 introduced the improved MG FF/M cannon, capable of firing the thin-walled, high-explosive Minengeschoss. This greatly increased the weapon’s effectiveness against both fighters and bombers.
Between 1 January and 1 September 1939, 1,091 Bf 109Es were delivered. Aircraft were produced by Messerschmitt at Regensburg, as well as by Erla, Fieseler and Wiener Neustädter Flugzeugwerke in Austria.
By the outbreak of war on 1 September 1939, twelve Luftwaffe Gruppen were equipped with Bf 109B, C, D or E variants.
Into Combat
The Bf 109 performed with considerable success during the campaigns in Poland, Scandinavia, the Low Countries and France. These operations gave the Luftwaffe a large cadre of combat-experienced fighter pilots and leaders before the Battle of Britain began.
German fighter tactics had been refined during the Spanish Civil War. The two-aircraft Rotte and four-aircraft Schwarm formations allowed pilots to maintain good visual coverage and protect one another’s blind spots far more effectively than the tighter formations initially used by the RAF.
Bf 109 pilots also employed Freie Jagd, or free-hunting fighter sweeps, in which they sought altitude and tactical advantage before engaging British aircraft. From superior height, a Bf 109 could dive rapidly upon an opponent and then use its climbing performance to regain altitude.
The Bf 109 in the Battle of Britain
By August 1940, twenty-three Luftwaffe Gruppen were operating the Bf 109E from airfields along the French Channel coast. The principal variants used during the campaign were the Bf 109E-1, E-3 and E-4, with the E-7 also appearing in the fighter-bomber role.
In combat, the relative strengths and weaknesses of the Bf 109E, Spitfire and Hurricane frequently cancelled one another out. Altitude, surprise, formation tactics and pilot experience were often more decisive than small differences in technical performance.
The Bf 109 and Spitfire were closely matched between approximately 12,000 and 17,000 feet. At altitudes above 20,000 feet, the Bf 109E generally possessed an advantage, while the Spitfire and Hurricane offered tighter turning performance.
The Bf 109 was an extremely stable gun platform and could withstand high-G manoeuvres. Its fuel-injected DB 601 engine allowed pilots to push directly into a negative-G dive without the temporary loss of power suffered by the carburettor-equipped Merlin engines in British fighters.
This allowed a German pilot to bunt abruptly into a dive to escape an attack or gain separation. British pilots often had to half-roll before following, ensuring that positive G maintained fuel flow to their engines.
The cannon-armed Bf 109E-3 and E-4 also possessed heavier firepower than the eight .303 inch Browning machine guns carried by most British fighters. The 20 mm shells could inflict severe damage with only a few hits.
The aircraft nevertheless had important weaknesses. Its cockpit was cramped, its undercarriage was unforgiving, and its high wing loading gave it a relatively wide turning circle and high stall speed. The Bf 109 was also less capable of absorbing battle damage than the more robust Hurricane.
Limited Range
The Bf 109E’s most serious operational limitation during the Battle of Britain was its short range. Operating from northern France, it could spend only a limited amount of time over southern England before fuel consumption forced it to return.
This prevented the fighter from operating north of the Thames for any extended period and severely restricted its tactical freedom. Bf 109 pilots frequently had to turn back before German bomber formations reached their targets or soon after combat began.
The problem became more serious when Luftwaffe fighters were ordered to provide close escort. Tied to slower bomber formations, Bf 109 pilots surrendered altitude, speed and freedom of manoeuvre—the very advantages that had made them most effective.
Instead of conducting free-hunting sweeps and engaging RAF fighters on favourable terms, they were increasingly required to remain near Heinkel He 111s, Dornier Do 17s and Junkers Ju 88s. This made the German fighters more predictable and reduced their ability to seize the initiative.
The shortcomings of the Bf 110 as a long-range escort fighter added to the pressure. The twin-engined Zerstörer proved vulnerable to Spitfires and Hurricanes and sometimes required protection from Bf 109s itself.
Fighter-Bomber Operations
During the later stages of the Battle of Britain, the Bf 109E was increasingly used in the Jagdbomber, or Jabo, role. The Bf 109E-7 could carry a 250 kg bomb beneath the fuselage on a centreline rack while retaining its fighter armament.
These aircraft conducted fast, low-level or high-altitude attacks against targets in southern England. Their small size and speed made them difficult to detect and intercept, although carrying a bomb reduced the fighter’s performance until the weapon was released.
The use of the Bf 109 as a fighter-bomber represented an attempt to maintain pressure on Britain while reducing the vulnerability associated with large bomber formations. It did not, however, overcome the Luftwaffe’s wider strategic and operational difficulties.
Losses During the Battle of Britain
By the end of the campaign, the Luftwaffe had lost 1,792 aircraft on operations, including 610 Bf 109s.
German Bf 109 pilots were credited with approximately 770 Spitfires and Hurricanes during the battle. As with the victory claims made by all participating air forces, these figures exceeded the enemy’s actual losses because of the difficulty of confirming aerial victories during confused, fast-moving engagements.
The high number of Bf 109 losses reflected not only combat with RAF fighters but also forced landings, fuel exhaustion, accidents and the consequences of operating over hostile territory. A damaged British fighter could often land within Britain, while a German aircraft suffering similar damage might be lost before reaching France.
Legacy
The Bf 109 was one of the most influential fighter aircraft of the Second World War. It combined a lightweight airframe, powerful engine, effective armament and excellent climbing performance in a design that remained capable of continuous development.
Later versions included the aerodynamically refined Bf 109F Friedrich, the more powerful Bf 109G Gustav and the final major production model, the Bf 109K Kurfürst.
More than 33,000 examples were produced, making the Bf 109 the most numerous fighter aircraft in history. It was flown by many of the highest-scoring fighter pilots of all time and was credited with destroying more enemy aircraft than any other fighter type.
Its achievements were accompanied by persistent weaknesses, including limited range, a cramped cockpit, difficult ground handling and increasingly demanding flying characteristics. Nevertheless, the Bf 109 remained a formidable combat aircraft from the Spanish Civil War until the final days of the Second World War.
Frequently Asked Questions
What was the Messerschmitt Bf 109?
The Messerschmitt Bf 109 was a German single-seat fighter that served as the principal aircraft of the Luftwaffe’s fighter force during the Second World War. It was Germany’s main fighter during the Battle of Britain and remained in production throughout the war.
Why is it called the Bf 109 rather than the Me 109?
The aircraft was designed while the company was still known as Bayerische Flugzeugwerke, so it received the official designation Bf 109. The name Me 109 became widely used later because the company was renamed Messerschmitt AG, but Bf 109 remained the aircraft’s official designation.
Why was the Bf 109 so effective?
The Bf 109 combined a lightweight airframe with a powerful fuel-injected engine, excellent climbing performance, effective radio equipment and heavy armament. It was also supported by experienced pilots using flexible Rotte and Schwarm formations developed during the Spanish Civil War.
Was the Bf 109 better than the Spitfire?
The Bf 109E and Spitfire Mk I were closely matched during the Battle of Britain. The Bf 109 generally possessed stronger climb and high-altitude performance, heavier cannon armament and the ability to perform negative-G manoeuvres. The Spitfire generally offered a tighter turning circle and lighter, more harmonious handling. Pilot skill, altitude and tactical position were often more important than the differences between the aircraft.
Could the Hurricane out-turn the Bf 109?
Yes. The Hurricane’s excellent manoeuvrability allowed it to turn more tightly than the Bf 109 in many circumstances. The German fighter instead relied on superior acceleration, climbing performance and energy-based tactics rather than prolonged turning engagements.
Why was the Bf 109’s range a problem?
The Bf 109E had limited endurance when operating from airfields in northern France. Its pilots could spend only a short period over southern England before fuel limitations forced them to return, restricting bomber escort operations and reducing their tactical flexibility.
What was the Bf 109E “Emil”?
The Bf 109E, known as the Emil, was the principal Luftwaffe fighter during the Battle of Britain. Powered by the fuel-injected Daimler-Benz DB 601 engine, it combined strong climb performance with either four machine guns or a mixed armament of machine guns and 20 mm cannon.
What weapons did the Bf 109E carry?
The Bf 109E-1 carried four 7.92 mm MG 17 machine guns. The Bf 109E-3 and E-4 retained two fuselage-mounted MG 17s but replaced the wing machine guns with two 20 mm MG FF or MG FF/M cannon.
Why could the Bf 109 dive away from British fighters?
The Bf 109’s fuel-injected Daimler-Benz engine continued operating during negative-G manoeuvres. The carburettor-equipped Merlin engines in the Spitfire and Hurricane could temporarily lose power if their pilots pushed directly into a steep dive, forcing them to half-roll before following.
Why was the Bf 109 used as a fighter-bomber?
Later in the Battle of Britain, some Bf 109Es were fitted to carry a 250 kg bomb. These Jagdbomber aircraft could conduct fast attacks against targets in southern England while retaining the ability to fight once their bombs had been released.
How many Bf 109s were lost during the Battle of Britain?
The Luftwaffe lost approximately 610 Bf 109s during the Battle of Britain. These losses included aircraft destroyed in combat, damaged beyond repair, lost in accidents or forced down before returning to German-held territory.
How many Bf 109s were built?
More than 33,000 Bf 109s were produced, making it the most numerous fighter aircraft in aviation history.
Are any Messerschmitt Bf 109s still flying today?
Yes. A small number of surviving Bf 109s and licence-built derivatives remain airworthy. Others are preserved in aviation museums and private collections around the world.