The piston-engine fighter planes developed shortly before and during the Second World War proved to be the last and greatest of their type. By the end of World War II, the first generation of jet fighters was coming into service in the air forces of the major powers. The new jets would very quickly sweep aside the last generation of piston-engine fighters in first line service, although the most numerous and successful of the old types would serve in second line service (mostly in the ground attack role) and in smaller air forces for many years after the War. These long lived types included the Bf 109, P-51 Mustang, F4U Corsair, Yak 3/9 and Spitfire. All are worthy of consideration as representing the best fighter of their generation.

However, my choice--and the subject of this article--is Willy Messerschmitt's Bf 109. I am not alone in this choice, as the well known aeronautical engineer, WW II aviation authority and best selling aviation author, Martin Caidin, was of the same opinion.

I would argue that the Bf 109 (also and equally well known as the Me 109) deserves to be considered at the top because of its innovative design, adaptability, longevity in service, huge production numbers (almost 35,000, making the 109 the most produced fighter of WW II by a wide margin) and historical importance. From the Bf 109's entry into service at the end of 1936 in the Spanish Civil War to the end of the Second World War in 1945 and the Israeli War of Independence in 1948, the 109 remained a front line air superiority fighter. This long run remains unprecedented in a time of rapid technological advances and extreme pressure, as the world's foremost military powers fought for their very survival.

Willy Messerschmitt and Walter Rethel designed the Bf109 in response to an official government request for a monoplane fighter. They, sensibly, designed their new fighter around the smallest airframe (length 28 feet, wingspan 32 feet) that could accommodate the most powerful motor available at the time, the liquid-cooled 680 HP Junkers Jumo 210A. This design philosophy was to serve the new fighter well during its long combat career.

The Bf 109 V1 prototype first flew on 28 May 1935. It was the first fighter to incorporate all of the features that would make the final generation of piston-engine fighters so successful during the Second World War. It was an all metal, stressed skin monocoque, single seat, monoplane fighter with an enclosed cockpit and retractable landing gear.

The "B," "C" and early "D" Bf 109 versions were powered by Jumo engines, but the late production 109-D models introduced the Daimler Benz DB-600 series motors with which all subsequent Bf 109 versions were to be equipped. This superb inverted V-12 engine was able to keep pace with the best of the Allied V-12's throughout the war. The DB-601A fitted in the Bf 109E-1 (1939) produced 1175 HP and the DB-605DCM fitted in the Bf 109K-4 at the end of the war (1945) produced 1800 HP (over 2000 HP emergency power with MW-50 methanol-water injection).

The Bf 109's most famous and successful early contemporary was probably the Hawker Hurricane Mk. I, a single seat monoplane fighter with an enclosed cockpit and retractable undercarriage that trailed the Bf 109 into service by a year or more. However, the Hurricane was a hybrid mix of old and new technology, as its fuselage was built on a tubular metal frame and fabric covered. Although a dangerous opponent in 1939-1940, the Hurricane was never quite the equal of the Bf 109 as an air superiority fighter and, unlike the 109, by 1942 the Hurricane was clearly inferior to newer designs. The Hurricane's obsolescent design was unable to keep up with the fast pace of wartime technological innovation.

Among Allied fighters, only the British Supermarine Spitfire proved to have a design as adaptable to improvements and innovations as the Messerschmitt Bf 109. Consequently, the Spitfire and Bf 109 remained deadly enemies (albeit with mutual respect from aces on both sides) throughout the war. Indeed, the Messerschmitt and Supermarine designers engaged in a continuous, war-long contest of technical one-upmanship.

The Spitfire is equally deserving of being called the best fighter of its generation, if only its service during and after WW II is considered. However, the Bf 109 went into service during the Spanish Civil War, well before the first Spitfire Mk. I's entered service in August 1938. Interestingly, Czech Bf 109's (Avia S-199) and Spitfires were purchased after WW II by the fledgling Israeli Air Force and used with telling effect in that country's 1948 war of independence, achieving air superiority flying against Royal Egyptian Air Force Spitfires.

The Me 109's track record is unparalleled. The Bf 109B entered service during the Spanish Civil War with the Condor Legion, where in 1937 it demonstrated its superiority against the Soviet Polikarpov I-16 monoplane fighter supplied to the Republican forces by the USSR.

When Germany invaded Poland in 1939 and France in 1940, well trained Luftwaffe pilots, mostly flying Bf 109D's, quickly achieved air superiority over the Polish, French and American Curtiss P-36 fighters they encountered.

Later in 1940, during the Battle of Britain, the Bf 109E (Emil) proved superior to the Hurricane and the equal of the famous Spitfire in air to air combat. This was tacitly admitted by the RAF, whose preferred interception technique was to have Hurricanes attack the German bombers while Spitfires engaged the 109 fighters.

By the time Germany invaded the Soviet Union in 1941 the I-16, although still constituting about 65% of the Soviet fighter force, was obsolete, while the improved and streamlined Bf 109F (Friedrich or Franz) that spearheaded the invasion was arguably the best air superiority fighter in the world at the time. In North Africa during 1941-1942, generally outnumbered Bf 109F pilots dueled with Spitfire Mk. V, Curtiss P-40 and late model Hurricanes fighters with positive results. The Bf 109F was probably the purest form of the design and the best dogfighter.

Later, during the 1943-1944 air war over Germany and on the Eastern Front, the Allies were able to establish overwhelming numerical superiority and field their latest generation of fighters. These included the American P-38, P-47 and P-51; British Spitfire Mk. IX and Hawker Typhoon; and the Soviet Yak 9. However, the Bf 109G (Gustav) series, powered by the larger displacement (1475 HP) DB 605A motor, remained competitive (when flown by pilots of equal ability) with the latest Allied fighters. The G-1 (pressurized cockpit), G-2 (not pressurized) and G-3 (wider tires and improved radio) models were the last 109's intended almost exclusively for fighter versus fighter combat. Like the prevous Friedrich series, they were armed with a rapid fire MG 151 20mm cannon firing through the propeller hub and two cowl mounted 8mm machine guns.

From 1944 on, British and American heavy bombers were successfully pounding German cities and industry into rubble with massive day and night raids. In the G-5 and subsequent Gustavs, 13mm machine guns replaced the 8mm cowl mounted guns of the Friedrich and early G-series. The numerically dominant G-6 series, the first "standardized" 109's, were designed to accept a variety of external stores. These included under wing 20mm and 30mm cannon packs, 210mm mortars, or a 551 pound bomb. This additional armament, advantageous when engaging heavy bombers or in close support of ground forces, degraded the fighter's air to air combat performance, leaving it at a disadvantage when confronted with superior numbers of the latest Allied fighters. The G-6 was sometimes referred to as the "Bulge" by German pilots, for the unsightly cowling protuberances required to contain its heavier armament. Flown "clean" (without external stores) the G-6 could hold its own in air to air combat.

The Gustav series culminated with the G-14 and G-10, the former preceeding the latter into service. These represented incremental improvements over the more numerous G-6 models. Powered by a more powerful DB 605D motor (1850 HP) the G-10, last and best of the Gustavs, achieved a top speed in clean condition of 426 MPH at 24,280 feet. Altogether, a total of some 30,000 Bf 109G's of all types were built.

It is worth noting that the Luftwaffe preferred to vector their less maneuverable (but heavily armed) FW 190 fighters against the daylight heavy bombers while Bf 109's engaged the escorting fighters. These tactics are reminiscent of the roles the RAF assigned to their Hurricane and Spitfire fighters during the Battle of Britain.

The final production Bf 109 variant was the aerodynamically refined "K," based on the G-10 airframe with the G-series bulges faired into the fuselage. The Bf 109K-4 was the production version and deliveries to Luftwaffe squadrons began in October 1944 and continued until the final collapse of the Third Reich in May 1945. The K-4 incorporated a pressurized cockpit for high altitude operation, a comfort lacking in contemporary Allied fighters. Even at this late date the Bf 109 remained a very impressive fighter with performance comparable to its adversaries. Consider the following specifications for top speed at best altitude and climb rate.

• Bf 109K-4: Maximum speed 452 MPH at 19,685 ft. (6 km); best climb 4920 ft./min. at 2963 ft., 3692 ft./min at 19,685 ft.
• Spitfire Mk. XIV: Maximum speed 439 MPH at 24,500 ft.; best climb 4700 ft./min. at 8,000 ft., 3700 ft./min. at 22,500 ft.
• P-51D: Maximum speed 437 MPH at 25,000 ft.; best climb 3320 ft./min at 5000 ft., 2450 ft./min. at 20,000 ft.
• Yak 3 (II): Maximum speed 407 MPH at 10,170 ft.; initial climb 3800 ft./min. (altitude unspecified)

It is remarkable that the first of the all metal, stressed skin monocoque, single seat, monoplane, piston engine fighters with an enclosed cockpit and retractable landing gear was able to remain so competitive with the final evolution of the type. Willy Messerschmitt's signature fighter was, indeed, a remarkable achievement. It deserves to be considered the best fighter of its generation.

Note: For additional reading about the Bf 109, see The Messerschmitt Bf 109 and The Best Fighter Planes of World War II. Both articles can be found on the Naval, Aviation and Military History website.