In April 1918, just six months before the end of the First World War, Germany introduced what would be the best fighter plane of the war. Although it came too late to prevent Germany's defeat, the Fokker D7 was test-flown by top ace Manfred von Richthofen, the Red Baron himself, and at the end of the war became the subject of its own special provision in the peace treaty.
Fokker D7 at the Smithsonian Air and Space Museum.
By the beginning of 1918, air superiority in the First World War, which had been swinging back and forth for the past three years, was turning in favor of England and France. The SPAD 13, SE5a and Sopwith Camel were dominating the German Fokker Dr1's and Albatross D5a's, and the German air service was looking for a replacement. Over 30 new designs were submitted.
One of these was from the Fokker company. Dutch aircraft designer Anthony Fokker had produced the famed Dr1 triplane. His new design, from chief engineer Reinhold Platz, was basically a biplane version of the triplane, with the same fuselage and tail assembly, but it was extensively modified. The lower wing was made shorter and thicker, and while the top surface was flat, a dihedral effect was produced by tapering the wing's thickness towards the tips. Like the Dr1, the new design had a small airfoil between the wheels, acting as a mini-wing. Unlike most aircraft of the time, which had wooden frameworks, the D7 airframe was made of metal tube.
To solve the problem of structural weakness in the wings, which had plagued the earlier Fokker and Albatros fighters, Fokker strengthened the wing spars and, instead of using a network of wing bracing wires, replaced them with V-shaped wing struts made from metal tubes, reducing drag. However, when Germany's leading air ace, Manfred von Richthofen, was invited to test-fly the new airplane in January 1918, he reported that while it was highly maneuverable, it was dangerously unstable, especially in a dive. Working quickly, Fokker lengthened the fuselage, added a stabilizing fin, and enlarged the tail rudder. With these modifications, Richthofen became an enthusiastic fan of the aircraft, and in February, the new design was selected for production as Germany's new frontline fighter. It was designated the Fokker D7.
The D7's began reaching combat units in April 1918, with some of the first going to Richthofen's squadron, Jasta 11. (Richthofen flew the D7 on a few missions, but was killed in his Dr1 triplane later in April.) The initial production D7's were fitted with a 160-horsepower inline Mercedes D.III engine. This, however, allowed the Entente SE5a's and Sopwith Camels to outclimb the Fokker, and to correct this problem the 185-horsepower 6-cylinder inline IIIa engine from BMW was rushed into production. With that change, the D7 became the best all-around fighter to fly in the war. It was faster and more maneuverable than Entente fighters, and its higher ceiling and climb rate allowed German pilots to gain the advantage of height. The powerful engine also allowed the D7 to climb nearly vertically without stalling, allowing it to attack enemy planes from below, unseen by the opposing pilot. The production model D7's were fitted with two .30 caliber machine guns, but some experimental models were fitted with a single .50-caliber (intended as a ground-attack weapon against tanks).
The Fokker plant was unable to produce the D7 quickly enough, and the Germans licensed the design to the Albatros and AEG companies. But materials shortages caused by the Entente's naval blockade crippled production, and in all, only 1,000 D7's were built during the last six months of the war; at war's end, about 770 of them were flying with around 40 German squadrons. Most of these used the smaller 165-horsepower engine.
The D7 quickly established its superiority to anything that the Entente could put up against it. In the month of August 1918 alone, the Fokkers shot down 565 British, French and American aircraft.
But while the German air forces were dominating the sky, the German army on the ground was collapsing. The summer offensive that was intended to win the war had failed, and as fresh American troops began to enter the trenches, the German army began to be pushed back. In November 1918, Germany asked for an armistice.
In the surrender treaty, Germany was forced to give up or destroy much of its military equipment, including its submarines and battleships. And in one specific provision, the treaty specified that "all machines of the Fokker D7 type" be turned over to the Allies.
As it turned out, Anthony Fokker was able to save enough spare parts for 120 D7's by smuggling them aboard a train into his native Holland. After the war, Fokker was able to re-start production and sell D7's to the air forces of several countries, including Holland, Belgium, Poland, Italy, Spain, Sweden, and Switzerland. Some of these countries were still flying D7s in the 1930's.
The United States shipped 142 captured D7's back to the US, where they were first test-flown for evaluation and then used as trainers (and some found their way into post-war Hollywood movies). Many of the D7's design features were incorporated into the US Navy's new carrier-based Boeing FB-1 fighter introduced in 1925.
One of the Fokker D7's brought to the US was captured just two days before the war ended, when German pilot Lieutenant Heinz Freiherr von Beaulieu-Marconnay mistakenly landed at an American airfield near Verdun. This was an Albatros-built version, which was shipped back to the US, test-flown a few times, and given to the Smithsonian Istitution in 1920. It was restored in 1961, and remains on display in the Air and Space Museum.