German Empire (1917)
Fighter Plane – 320 Built
The Fokker Dr.I was a triplane built by Fokker-Flugzeugwerke during the First World War. The design, based off of Britain’s Sopwith Triplane, is well known thanks to the Red Baron, Manfred von Richthofen, for being the plane in which he scored his final kills.
A Borrowed Idea
In the early part of 1917 the Sopwith Triplane of the Allies began appearing on the battlefield, quickly trouncing German Albatros D.III fighters with its superior maneuverability and climbing ability. The Idfleig, the German bureau overseeing aircraft design immediately ordered development of a triplane, known as dreidecker (3 winged) in German.
Nearly all of the German aircraft manufacturers followed suit. Fokker set about to develop its own triplane by modifying an unfinished prototype biplane. This initial prototype, like Sopwith’s design, utilized a rotary engine and steel tube fuselage. However the initial prototype, the V.4 did not have external interwing bracing. The next prototype, the V.5 introduced bracing between the wings to minimize flexing on the upper wing. The prototypes were met with much excitement for their exceptional maneuverability and climb rate over anything else the Germans had previously produced. The Red Baron himself, Manfred von Richthofen was believed the Dr.I held much promise for the fortunes of German air power and demanded his superiors to commence production immediately, as well as promising his men that they would soon be able to “move like devils and climb like monkeys.”
The appearance of the Dr.1 is characterized by its three-wing design – therefore dubbed a ‘triplane.’ The design also featured small sustentation surface of an aerofoil shape mounted between the wheels of the landing gear. The tail was also completely mobile with unbalanced ailerons possessing more surface area than the ailerons of the upper wing. The wings had deep section hollow box-spars that provided lightweight strength to the wings. The lack of interplane struts on the initial prototype resulted in excessive wing vibration during flight, so interplane struts were added. The ribs were of plywood, as well as the leading-edges covers at the spar, with the leading-edges made of wire. The middle wings had some cut-outs to improve downward visibility of the pilot. The fuselage was constructed using welded steel-tubing bracing with diagonal wires to create the rigid box-shaped structure, being a fabric-covered with triangular plywood fillets, except the undercarriage and center-section, which were made of steel streamlined tubing.
The tail-plane had a triangular shape, being framed in steel tubing the same way as the balanced rudder and elevators. The wheels featured an elastic shock cord, while a steel-tipped tailskid was installed at the rear.
The first prototype Dr.1 flew in July of 1917. Production of the Dr.I commenced on August 11th of 1917. In preproduction the triplane carried the designation F.I. Two were made and issued to Richthofen and Leutenant Werner Voss. These two aces promptly used these planes on the battlefield, scoring kills within the first few days of flying in early September. Voss took to the skies on August 28th and by September 11th had scored 8 kills.
The result of this evaluation period led Voss and Richthofen to recommend the Dr.I for production as soon as possible, declaring it superior to the Sopwith Triplane. Orders were placed for 300 Dr.I’s.
On September 14th the commander of Jasta 11, OberLeutnant Kurt Wolff was shot down whilst flying Richthofen’s F.I by a new Sopwith Camel of Britain’s Naval 10 squadron. Voss, whilst flying on September 23rd, scored his 48th victory just before being shot down in an epic dogfight wherein he managed to damage all 7 of his opponent’s SE-5a’s in the skirmish.
The Fokker Dr.I in Use
The Dr.I, upon its arrival to the battlefield in October was well regarded for its climbing ability and light controls. The ailerons were not very effective, however the tailplane elevator and rudder controls were very yielding. Rapid turns to the right were very quick thanks to the directional instability afforded by the rotation of the rotary engine, a characteristic that was taken advantage of by pilots.
Although not a particularly fast plane, it balanced this shortcoming with great maneuverability thanks to its light weight, while also having good upward visibility. It also had a decent climb rate, characteristics that all seemingly made the Dr.I a formidable adversary to its Allied opponent, the Sopwith Camel. This made of the Dr.1 a good aircraft for dogfights, yet structural and construction problems in the wings would hamper the aircraft’s promising initial assessment.
- Crew: One
- Length: 5.77 m (18 ft 11 in)
- Wingspan: 7.19 m (23 ft 7 in)
- Height: 2.95 m (9 ft 8 in)
- Wing area: 18.70 m2 (201 ft2)
- Empty weight: 406 kg (895 lb)
- Loaded weight: 586 kg (1,291 lb)
- Zero-lift drag coefficient: 0.0323
- Drag area: 0.62 m2 (6.69 ft2)
- Aspect ratio: 4.04
- Powerplant: 1 × Oberursel Ur.II 9-cylinder rotary engine, 82 kW (110 hp)
- Maximum speed: 185 km/h at sea level (115 mph at sea level)
- Stall speed: 72 km/h (45 mph)
- Range: 300 km (185 mi)
- Service ceiling: 6,100 m (20,000 ft)
- Rate of climb: 5.7 m/s (1,130 ft/min)
- Lift-to-drag ratio: 8.0
- 2 × 7.92 mm (.312 in) “Spandau” lMG 08 machine guns.