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Fokker Dr.I

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Fokker Dr.I
Type Fighter
Manufacturer Fokker-Flugzeugwerke
Designed by Reinhold Platz
Maiden flight 5 July 1917
Primary user Luftstreitkräfte
Number built 320

The Fokker Dr. I Dreidecker (triplane) was a World War I fighter aircraft designed by Reinhold Platz and built by Fokker-Flugzeugwerke. The Dr.I saw widespread service in the spring of 1918. It became renowned as the aircraft in which Manfred von Richthofen gained his last 20 victories, and in which he was killed on 21 April 1918.

Design and development

Fokker F.I (serial 102/17)

In April 1917, the Royal Naval Air Service (RNAS) introduced the Sopwith Triplane. The Sopwith swiftly proved itself superior to the Albatros and Halberstadt scouts then in use by the German Air Service. In response, the Idflieg immediately solicited designs for new triplane scouts. No fewer than 11 German aircraft manufacturers, including Albatros, Pfalz, AEG, DFW, Schütte-Lanz, and Euler, responded with triplane prototypes. Most showed little promise, though limited production of the Pfalz Dr. I was undertaken.

The Fokker works responded with the V.3, a small, rotary-powered triplane with a tubular-steel frame fuselage and thick cantilever wings. Initial tests revealed deficiencies in the V.3, particularly regarding control forces. Instead of submitting the V.3 for a type test, Fokker produced a revised prototype designated V.4. The most notable changes were the introduction of horn-balanced ailerons and elevators, as well as longer-span wings. The V.4 also featured interplane struts, which were not necessary from a structural standpoint, but which minimized wing flexing.

The V.4 proved superior to the triplane prototypes submitted by the other manufacturers. After a type test, Idflieg issued an immediate production order.

Operational history

Triplanes of Jasta 26 at Erchin, France

Two pre-production triplanes, designated F.I, were delivered to Jastas 10 and 11 for combat evaluation. These aircraft, serials 102/17 and 103/17, were the only machines to receive the F.I designation. They arrived at Markebeeke, Belgium on 28 August, 1917. Richthofen first flew 102/17 on 1 September 1917 and shot down two enemy aircraft in the next two days. He reported to the Kogenluft (Kommandierender General der Luftstreitkräfte) that the F.I was highly satisfactory. The combat debut of the triplane was short-lived, however. Kurt Wolff, Staffelführer of Jasta 11, was shot down in 102/17 on 15 September, and Werner Voss, Staffelführer of Jasta 10, was killed in 103/17 on 23 September. Delivery of production machines, designated Dr.I, commenced in October. These aircraft were identical to the F.I except for the addition of wingtip skids. All aircraft were delivered to squadrons within Richthofen's Jagdgeschwader 1.

Compared to the Albatros and Pfalz fighters it replaced, the Dr.I offered remarkable maneuverability and initial rate of climb. The ailerons were light but not very effective. The rudder and elevator controls were light and powerful. Rapid turns, especially to the right, were facilitated by the triplane's marked directional instability. Vizefeldwebel Franz Hemer of Jasta 6 said, "The triplane was my favorite fighting machine because it had such wonderful flying qualities. I could let myself stunt — looping and rolling — and could avoid an enemy by diving with perfect safety. The triplane had to be given up because although it was very manoeuvrable, it was no longer fast enough."

As Hemer noted, the Dr.I was considerably slower than contemporary Allied fighters in level flight and in a dive. Due to the low-compression Oberursel Ur.II, a clone of the Le Rhône 9J rotary engine, performance fell off dramatically at high altitudes. As the war continued, the lack of castor oil made rotary operation more difficult. The poor quality of German ersatz lubricant resulted in many engine failures, particularly during the summer of 1918.

Wing failures

Heinrich Gontermann's crashed triplane (serial 115/17)

On 30 October 1917, Leutnant Heinrich Gontermann, commander of Jasta 15 and a 39 victory ace, was killed when his triplane broke up in flight. Leutnant Günther Pastor was killed on the following day under similar circumstances. The remaining triplanes were immediately grounded pending an inquiry. Idflieg convened a Sturzkommission (crash commission) which concluded that poor construction and lack of waterproofing caused the wing ribs to disintegrate and the ailerons to break away.

In response to the crash investigation, Fokker improved quality control on the production line, particularly varnishing of the wing spars and ribs, to keep moisture from destroying the wing. Fokker also strengthened the rib structures and the attachment of the auxiliary spars to the ribs. Existing triplanes were modified at Fokker's expense. Idflieg authorized the triplane's return to service in late November 1917, and production resumed in early December. Despite corrective measures, the Dr.I continued to suffer from wing failures. On 18 March 1918, Lothar von Richthofen was seriously injured in a crash landing after the upper wing of his Dr.I collapsed in flight. Postwar research revealed that poor workmanship was not the only cause of the triplane's structural failures. In 1929, National Advisory Committee for Aeronautics (NACA) investigations found that the upper wing carried a higher lift coefficient than the lower wing — at high speeds it could be 2.55 times as much.


Fokker Dr.I (serial 152/17)

Very few triplanes survived the Armistice. Serial 528/17 was retained as a testbed by the Deutschen Versuchsanstalt für Luftfahrt (German Aviation Research Institute) at Adlershof. After being used in the filming of two movies, 528/17 is believed to have crashed sometime in the late 1930s. Serial 152/17, in which Manfred von Richthofen obtained three kills, became the centerpiece of Germany's new aviation museum in Berlin. During World War II, it was evacuated to Poland for safekeeping. Its subsequent fate is unknown, but 152/17 is presumed to have been destroyed near the end of the war. Today, no known original example of the Dr.I survives.


  • V3 - Initial prototype
  • V4 - First production prototype
  • V5 - Fitted with a Goebel Goe.III engine
  • V6 - Larger version, with a Mercedes D.II engine
  • V7 - Fitted with a Siemens-Halske Sh.III engine
  • V10 - Fitted with an Oberursel Ur.III engine


Template:Country data German Empire

Specifications (Dr. I)

Data from Quest for Performance[1]

General characteristics

  • Drag area: 6.69 ft² (0.62 m)
  • Aspect ratio: 4.04 Performance
  • Lift-to-drag ratio: 8.0Armament

    2x 7.92 mm "Spandau" LMG 08/15 machine guns.

    See also

    Comparable aircraft




    • Leaman, Paul. Fokker Dr.I Triplane: A World War One Legend. Hersham, Surrey, UK: Classic Publications, 2003. ISBN 1-90322-328-8.
    • Green, William and Swanborough, Gordon. The Great Book Of Fighters. St. Paul, Minnesota: MBI Publishing, 1994. ISBN 0-83173-939-8.
    • Weyl, A.R. Fokker: The Creative Years. London: Putnam, 1988. ISBN 0-85177-817-8.

    External links

    Wikimedia Commons has media related to:

    Template:Idflieg Dr-class designations Template:Fokker aircraft

    cs:Fokker Dr.I da:Fokker Dr.I de:Fokker Dr.I es:Fokker Dr I fr:Fokker Dr.1 Triplan id:Fokker Dr.I it:Fokker Dr.I hu:Fokker Dr.I ms:Fokker Dr.I nl:Fokker Dr.I ja:フォッカー Dr.I no:Fokker Dr.I pl:Fokker Dr.I pt:Fokker Dr. I simple:Fokker Dr.I fi:Fokker Dr.I sv:Fokker Dr.I

    This article is licensed under the GNU Free Documentation License.
    It uses material from the Wikipedia article "Fokker Dr.I".