Heinkel He 112

• Role: Monoplane Fighter
• Manufacturing Nation: Germany
• Introduced: 1936
• Crew: 1
• Maximum speed: 488 km/h (303 mph)
• Range: 1,100 km (684 mi)
• Armaments: Machine guns and cannons

The He 112 was developed while the Germans were still under the Treaty of Versailles as a "high speed courier aircraft" in a poor attempt to disguise the construction of fighter planes. The 112 introduced features that would become standard on German fighters, including retractable landing gear and all metal construction. However, due to the speed of technology advancement, the Germans ultimately bypassed mass production of the 112 in favor of the Messerschmitt Bf 109. Some remaining He 122's were sold to other nations eager to upgrade from biplanes, including Spain, where it saw action in the Spanish Civil War. A few He 112's ended up being used as test aircraft, and became the first planes to test Germany's experimental jet propulsion engines.

Fiat G.50

• Role: Monoplane Fighter
• Manufacturing Nation: Italy
• Introduced: 1936
• Crew: 1
• Maximum speed: 484 km/h (301 mph)
• Range: 670 km (418 miles)
• Armaments: Machine guns

The Fiat G.50 Freccia ("Arrow") was the first Italian monoplane fighter with an enclosed cockpit and retractable landing gear to go into production. It was one of the most maneuverable planes in the world when first developed, but given the rapid advancements in fighters, it was soon surpassed by other aircraft. Nevertheless, it saw action in many campaigns, from the Spanish Civil War under the Nationalists, to North Africa and The Greek Campaign, where the Italians dominated in combat against the RAF's Gloster Gladiator. This changed dramatically when the RAF began using the Hurricane, and the G.50 was soon replaced by the Macchi C.200. The G.50 was used most extensively as an export to the Finnish Air Force in Finland's two wars against the Soviet Union.

Nakajima Ki-27

• Role: Monoplane Fighter
• Manufacturing Nation: Japan
• Introduced: 1937
• Crew: 1
• Maximum speed: 444 km/h (275 mph)
• Range: 630 km (390 mi)
• Armaments: Machine guns and bombs

The Nakajima Ki-27 was the main fighter aircraft used by the Imperial Japanese Army Air Force up until 1940, and a total of over 3368 were built. It's extraordinary maneuverability led to great early success in the war against China, and this trait influenced Japanese design philosophy for fighters, which tended to prioritize agility over speed, armor, and additional weapons. The Ki-27 was used throughout the war, often as a bomber escort, and towards the end was fitted out with 500 kg (1,100 lb) of explosives and used as a kamikaze plane.

Dewoitine D.500

• Role: Monoplane Fighter
• Manufacturing Nation: France
• Introduced: 1935
• Crew: 1
• Maximum speed: 402 km/h (250 mph)
• Range: 700 km (435 mi)
• Armaments: Machine guns or cannon

The Dewoitine D.500 was an all-metal, open-cockpit, fixed-undercarriage monoplane. One variation featured a 20 mm cannon in the propeller hub instead of nose mounted machine guns. Like many early monoplane designs, it was soon replaced by a new generation of fighter aircraft with enclosed cockpits and retractable undercarriage. A number of D.500's were exported to Spain, where they saw action with the Republican forces in the civil war. Some were also exported to China and used in the war with Japan.

Boeing P-26

• Role: Monoplane Fighter
• Manufacturing Nation: United States
• Introduced: 1933
• Crew: 1
• Maximum speed: 234 mph (377 km/h)
• Range: 360 mi (580 km)
• Armaments: Machine guns and bombs

The diminutive "Peashooter", as it became affectionately known by service pilots, was faster than previous American combat aircraft, but it was also an anachronism. Although the P-26 introduced a modern monoplane design, worldwide fighter aircraft developments soon outstripped the P-26. In Europe the Messerschmitt Bf 109 and Hawker Hurricane (which both flew for the first time in 1935) were more representative of contemporary monoplane fighter designs. However, the P-26 was easy to fly and remained in active service for many years until the United States entered World War II. It saw action with the Chinese Air Force in aerial combat against Japanese carrier fighters--the first recorded monoplane dogfights in Asia. During the Japanese invasion of the Philippines, P-26's managed to shoot down several Japanese planes before the entire squadron was either destroyed on the ground or overwhelmed by Japanese Zeroes.

Polikarpov I-16

• Role: Monoplane Fighter
• Manufacturing Nation: USSR
• Introduced: 1934
• Crew: 1
• Maximum speed: 525 km/h (326 mph)
• Range: 700 km (435 mi (with drop tanks))
• Armaments: Machine guns and bombs

The Polikarpov I-16 was a Soviet fighter aircraft of revolutionary design; it was the world's first cantilever-winged monoplane fighter with retractable landing gear. The I-16 was introduced in the mid-1930s and formed the backbone of the Soviet Air Force at the beginning of World War II. 8,644 were built. The diminutive fighter featured prominently in the Second Sino-Japanese War. In the Spanish Civil War, the I-16 dominated the German and Italian made biplane fighters, and remained unchallenged until the arrival of the Messerschmitt Bf 109. Even then, it was able to hold its own, countering the 109's superior slashing dive capability with it own rapid barrel rolls. Skilled pilots took advantage of its superior horizontal maneuverability and liked the aircraft enough to resist the switch to more modern fighters. It also fared well against Japanese fighters in the late 1930's, until the introduction of the more advanced Zero, which swept the I-16 from the skies with impunity.

Hawker Hurricane

• Role: Monoplane Fighter
• Manufacturing Nation: UK and Canada
• Introduced: 1935
• Crew: 1
• Maximum speed: 340 mph (547 km/h)
• Range: 600 mi (965 km)
• Armaments: Machine guns or cannons and bombs

Together with the Spitfire, this iconic fighter was significant in enabling the Royal Air Force to win the Battle of Britain of 1940, accounting for the majority of the RAF's air victories. Its extraordinary success was in part due to the quality of the pilots, excellent overall performance and its armament: eight wing-mounted machine guns or four 20mm Hispano cannon firing incendiary rounds, and a bomb load of up to 500 lb (230 kg). About 14,000 Hurricanes were built and served in all the major theatres of the Second World War. Already obsolete when first produced (the early models were still fabric-covered) the Hurricane evolved through several versions and adaptations, resulting in a series of aircraft which acted as interceptor-fighters, fighter-bombers, and ground support aircraft. Ease of assembly allowed them to be easily crated, shipped, and assembled. It could withstand significant damage and still survive, and was relatively easy and inexpensive to repair. It could also be carrier-based, with spares stored and assembled as needed. Over 4000 were supplied to allied nations during the war.

Fokker D.XXI

• Role: Monoplane Fighter
• Manufacturing Nation: Netherlands
• Introduced: 1938
• Crew: 1
• Maximum speed: 460 km/h (285 mph)
• Range: 930 km (574 mi)
• Armaments: Machine guns and bombs

The Fokker D.XXI was a low wing monoplane with a steel tube fuselage covered in large part by fabric, with wooden wings and a fixed spatted undercarriage. Although superior German and British planes were already in use, when it entered service in 1938 the D.XXI was a quantum leap forward for the Dutch Army Aviation Group. Until then its fighter force had consisted of aging biplanes with open cockpits. The new Fokker proved to be an extremely sturdy aircraft capable of attaining a speed of 700 km/h in a dive. During the war against Germany in 1940, they acquitted themselves well against the more advanced German fighters, despite the D.XXI's much slower speed and lighter armament, until they were overwhelmed by sheer numbers. The D.XXI's rugged design also made it quite effective for the Finnish Air Force in their Winter War against the Soviet Union.

Ikarus IK 2

• Role: Monoplane Fighter
• Manufacturing Nation: Yugoslavia
• Introduced: 1935
• Crew: 1
• Maximum speed: 250 km/h (155 mph)
• Range: 700 km (435 mi)
• Armaments: Machine guns and cannon

The Ikarus IK-2 was a 1930s high-wing, all-metal, single seat, monoplane fighter aircraft of indigenous design that gave the pilot an excellent view and featured a 20 mm HS-404 cannon mounted under the engine in addition to guns. During its testing phase, in aerial combat, the IK-2 outperformed biplanes in all respects. When German forces invaded Yugoslavia the IK-2s were used to repel invading aircraft and for strafing advancing German columns. After this campaign, the surviving aircraft were given by Germany to the newly created Air Force of the Independent State of Croatia.

Brewster Buffalo

• Role: Monoplane Fighter
• Manufacturing Nation: Australia (USA export)
• Introduced: 1939
• Crew: 1
• Maximum speed: 301 mph (484 km/h)
• Range: 1,000 mi (1,600 km)
• Armaments: Machine guns and cannon

Originally developed in the USA as a carrier fighter, the new Brewster fighter had a modern look with a stubby fuselage, mid-set monoplane wings and a host of advanced features. It was all-metal, with flush-riveted, stressed aluminum construction, although control surfaces were still fabric-covered. Eventually the US Navy turned to newer planes, and Great Britain purchased approximately 200 of the planes and sent them to Australia just prior to the outbreak of war with Japan. They represented the core of the Australian Air Force and were used by Commonwealth forces throughout the south Pacific, including Burma, Malaya, and Singapore.

PZL P 11

• Role: Monoplane Fighter
• Manufacturing Nation: Poland
• Introduced: 1934
• Crew: 1
• Maximum speed: 390 km/h (233mph)
• Range: 550 km (341 mi)
• Armaments: Machine guns and bombs

The PZL P.11 was a Polish fighter aircraft, designed in the early 1930s by PZL in Warsaw. It was briefly considered to be the most advanced fighter aircraft design in the world. The PZL P.11 served as Poland's primary fighter defense in the Polish campaign of 1939, but by that point was outdated due to rapid advances in aircraft design. In the first air battles of WWII, the P.11's acquitted themselves well, despite being slower than even the German bombers. By 1939, most had seen years of service, yet in the defense of Poland the P.11 is credited with at least 110 victories for the loss of about 100 of their own. The P.11 was the first aircraft shot down in WWII, and also the first allied craft to shoot down a German plane (the two events occurring about 20 minutes apart). After Poland's surrender, the remaining P.11's were flown to Romania and used by the Romanian Air Force.