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
Photo Description: Messerschmitt Bf 109Es of Jagdgeschwader 26 in August 1940.
The Messerschmitt Bf 109 – often informally referred to as the Me 109 – was a German single-seat fighter aircraft that served as the backbone of the Luftwaffe’s Jagdwaffe (fighter force) throughout the Second World War. Designed by Willy Messerschmitt and Robert Lusser at Bayerische Flugzeugwerke (BFW), the aircraft was developed in response to a 1933 specification issued by the Reichsluftfahrtministerium (RLM) for a modern monoplane fighter to replace the obsolete Arado Ar 64 and Heinkel He 51 biplanes then in service. Messerschmitt aimed to produce the lightest possible airframe built around the most powerful inline engine available, resulting in a compact and streamlined all-metal low-wing monoplane with retractable undercarriage, automatic leading-edge slats, and a fully enclosed cockpit—radical features for a frontline fighter at the time.
Many of the aircraft’s innovations were derived from the earlier Bf 108 Taifun, a successful four-seat sport and touring aircraft. The first prototype, Bf 109 V1, made its maiden flight on 28 May 1935 at Haunstetten, near Augsburg. Since the intended Junkers Jumo 210A engine was not yet ready, the prototype was fitted with a Rolls-Royce Kestrel V engine for its initial trials. After successful evaluation at the Luftwaffe test center at Rechlin, the Bf 109 V1 was sent to Travemünde to compete against rival designs submitted by Arado, Focke-Wulf, and Heinkel. The aircraft’s superior speed and climb rate marked it as the front-runner despite reservations from test pilots regarding its narrow-track undercarriage, high wing loading, and confined cockpit.
In November 1936, the RLM declared the Bf 109 the winner of the competition, especially after being alarmed by reports of Britain’s new monoplane fighter, the Supermarine Spitfire. BFW had already begun developing subsequent prototypes. The Bf 109 V2, completed in October 1935, was the first to fly with the intended Jumo 210A engine. The Bf 109 V3, which flew in mid-1936, was the first armed version, equipped with two synchronized 7.92 mm MG 17 machine guns mounted over the engine cowling and firing through the propeller arc.
The initial production model, the Bf 109A, was lightly armed with two MG 17s. However, when it became known that the British Hawker Hurricane and Spitfire would each carry eight machine guns, the RLM pushed for increased firepower. The Bf 109B (“Bertha”) introduced a third machine gun mounted to fire through the propeller hub, though this setup was later replaced by a 20 mm MG FF cannon, which proved mechanically unreliable when mounted inside the engine. The Bf 109B-1 entered Luftwaffe service in early 1937 and was soon deployed to Spain with the Condor Legion, where it saw its combat debut during the Spanish Civil War. Lessons learned in Spain led to refinements, including the Bf 109C (“Clara”), with two additional MG 17s mounted in the wings, and the Bf 109D (“Dora”), which used the stopgap Jumo 210Da engine due to shortages of the preferred Daimler-Benz DB 600.
By late 1938, the Luftwaffe received the definitive Bf 109E (“Emil”), powered by the new DB 601A-1 engine with direct fuel injection. The Emil featured twin underwing radiators and a three-bladed, variable-pitch propeller. The Bf 109E-1 was armed with four MG 17 machine guns—two in the cowling and two in the wings – while the E-3 introduced 20 mm MG FF cannons in place of the wing-mounted MG 17s. The E-4, which appeared in spring 1940, used the improved MG FF/M cannons capable of firing Minengeschoss (mine-shell) high-explosive rounds, increasing its lethality.
The Bf 109E became the Luftwaffe’s primary frontline fighter during the Battle of Britain. By August 1940, twenty-three Gruppen were equipped with the type. Its DB 601 engine gave the aircraft a key advantage: it could perform negative-G maneuvers without fuel starvation – unlike the carburettor-equipped Rolls-Royce Merlin engines in British fighters. This allowed Bf 109 pilots to dive quickly out of combat. In terms of firepower, the wing-mounted cannons on the E-3 and E-4 variants delivered greater destructive capability than the eight .303 inch Browning machine guns fitted to both the Spitfire and Hurricane.
However, the Bf 109 had limitations. Chief among them was its short range. With an endurance of less than 90 minutes, it had little more than 10–15 minutes for combat over southern England before needing to return to airfields in northern France. This forced Bf 109 units into a close-escort role – protecting Heinkel He 111, Dornier Do 17, and Junkers Ju 88 bombers – instead of gaining and holding air superiority, which greatly reduced their effectiveness in offensive operations. Meanwhile, the Bf 110 Zerstörer, originally intended as a long-range escort fighter, proved vulnerable to British single-engine fighters and often required its own protection.
In the later stages of the Battle, the Bf 109E was also used in the Jagdbomber (Jabo) role, carrying a 250 kg (550 lb) bomb under the fuselage for fighter-bomber missions against targets in southern England. Though it achieved some success in this capacity, it remained primarily a defensive adaptation rather than a strategic shift.
Despite its drawbacks, the Bf 109’s performance in 1940 made it one of the finest fighters of its era. Throughout the war, the aircraft was continuously developed, evolving into later models such as the Friedrich (Bf 109F), Gustav (Bf 109G), and Kurfürst (Bf 109K). Over 33,000 examples were built, making it the most produced fighter aircraft in history.