Fokker Dr.I

Fokker Dr.I
Type:	Fighter and reconnaissance aircraft
Design country:	German Empire
Manufacturer:	Fokker Flugzeugwerke , Schwerin
First flight:	July 5, 1917
Commissioning:	1917
Production time:	1917-1918
Number of pieces:	420

The Fokker Dr.I was a triplane - fighter aircraft of the Fokker aircraft factory in Schwerin . The aircraft used by the German Army in the First World War from 1917 onwards became famous in particular through the most successful fighter pilot of the First World War, Manfred von Richthofen (the "Red Baron"), who scored 19 of his 80 aerial victories in fully or partially red-painted Fokker triplane and also died in a Dr.I.

development

The Dr.I arose from the desire for a copy of the British three-decker Sopwith Triplane , whose good flight performance and maneuverability had impressed the German fighter pilots. Even Manfred von Richthofen had expressed its appreciation of the Sopwith triplane. Instead of building an exact copy of the Sopwith Triplane, as expected from the inspection of the air force, Fokker's designer Reinhold Platz created his own design, which was adapted to Fokker's production technology. Platz was initially not at all enthusiastic about the idea of ​​building a three-decker and began to construct a conventional double-decker. Anthony Fokker then put Platz under pressure and so the Fokker V.4 was created as a three-decker.

designation	comment
D.VI / V.4	Triplane that led to Dr.I; 4 pieces built
V.5	Fokker-internal modifications to the prototype of the V.4
FI / Dr.I	FI: early serial designation of the Fokker three-decker, but this was changed to Dr.I very soon

general structure

The Fokker triplane initially had cantilever wings, later they were supplemented by struts on the outer wing due to the occurrence of wing vibrations. Although this type of construction tended to promise low air resistance due to the lack of tensioning wires , this advantage did not come into play due to the high resistance of three wings arranged closely one above the other.

Load-bearing structure

The basic construction of the aircraft consisted of a fuselage frame, which was welded together from 10-35 mm thick steel tubes, and a wooden structure with metal fittings and rudder surfaces made of steel tube.

Wooden parts

Glued plywood was used almost exclusively for the wooden components, as this is more flexible and more resilient than components made of solid wood. Depending on the purpose and load, pine, fir and birch were used and some were glued together. The ribs of the wings were made of birch plywood, onto which a layer of fir wood was glued on the outside. The wing spars were made of glued pine plywood. The milk protein product casein glue was used as wood glue .

Covering

The covering of the aircraft consisted of simple linen fabric . The fabric was flattened to close the relatively large gaps between the steel pipes. After the aircraft had been covered, the fabric was coated with a stretch varnish made of cellulose acetate and thereby stretched and sealed against wind and water. Aluminum was also used on a few non-load-bearing parts, such as the engine cover.

commitment

The Fokker triplane, which was equipped with a 110 hp rotary engine , was relatively slow compared to other fighter aircraft, but thanks to its thick wing profile and low weight , it could climb very steeply at low speed and was unsurpassed in maneuverability. Even the British Sopwith Camel , which is considered to be very agile , was able to curve out with the Fokker three-decker. Manfred von Richthofen to Dr.I: "... agile like the devil and climb like the monkeys."

On September 1, 1917, the first Dr.I arrived at the front. Between the middle of September and the beginning of November 1917 there were several fatal crashes due to a weak wing construction, which meant that the Dr.I was temporarily withdrawn from service. From February 1918 the triplane was used again at the front after Fokker had reinforced the wings. The Fokker Dr.I was produced in a comparatively small number of 420 copies until May 1918.

Performance comparison

Performance comparison of single-seaters in the front line at the end of the First World War :

Surname	Country	First flight	Commissioning	Engine power	Max. speed	Takeoff mass	Armament ( MG )	Summit height	number of pieces
Albatros D.III	German Empire	1916-08-01	1917-01-15	170 hp	165 km / h	886 kg	2	5,500 m	1352
SE5a	United Kingdom	1916-11-22	1917-03-15	200 hp	222 km / h	880 kg	2	5,185 m	5205
Sopwith Camel	United Kingdom	1916-12-31	1917-06-15	130 hp	185 km / h	659 kg	2	5,791 m	5490
Sopwith Dolphin	United Kingdom	1917-03-23	1918-02-15	200 hp	211 km / h	890 kg	2	6,100 m	2072
Albatros D.Va	German Empire	1917-04-15	1917-07-15	185 hp	187 km / h	937 kg	2	6,250 m	2562
Palatinate D.IIIa	German Empire	1917-04-15	1917-08-15	180 hp	181 km / h	834 kg	2	6,000 m	750
SPAD S.XIII	France	1917-04-30	1917-05-31	220 hp	222 km / h	820 kg	2	6,650 m	8472
Nieuport 28	France	1917-06-14	1918-03-15	160 hp	195 km / h	740 kg	2	5,200 m	300
Fokker Dr.I	German Empire	1917-07-05	1917-09-01	130 hp	160 km / h	585 kg	2	6,500 m	420
Sopwith Snipe	United Kingdom	1917-10-31	1918-08-30	230 hp	195 km / h	955 kg	2	6,100 m	497
LFG Roland D.VIa	German Empire	1917-11-30	1918-05-15	160 hp	190 km / h	820 kg	2	5,500 m	353
Siemens-Schuckert D.IV	German Empire	1917-12-31	1918-08-15	160 hp	190 km / h	735 kg	2	8,000 m	123
Fokker D.VII	German Empire	1918-01-24	1918-04-15	180 hp	189 km / h	910 kg	2	6,000 m	800
Fokker D.VIIF	German Empire	1918-01-24	1918-04-15	226 hp	205 km / h	910 kg	2	7,000 m	200
Palatinate D.VIII	German Empire	1918-01-24	1918-09-15	160 hp	190 km / h	740 kg	2	7,500 m	120
Palatinate D.XII	German Empire	1918-03-31	1918-07-15	160 hp	180 km / h	902 kg	2	5,640 m	750
Fokker D.VIII	German Empire	1918-05-31	1918-07-31	110 hp	204 km / h	605 kg	2	6,300 m	289

Technical specifications

Parameter	Data
crew	1
length	5.75 m
Wingspan above	7.20 m
Center span	6.23 m
Wingspan below	5.73 m
height	2.95 m
Wing area	18.70 m²
Empty mass	383 kg
Max. Takeoff mass	585 kg
engine	a 9-cylinder rotary engine Oberursel Ur.II 1
power	110 hp
Displacement	15.1 l
Engine ground	140 kg
Top speed	160 km / h in 2800 m 140 km / h in 4200 m
Climb performance	2:54 min climb time for 1000 m altitude
Max. Altitude	6500 m
Flight duration	1:30 h
Armament	2 rigid, synchronized MG 08/15 , firing through the propeller circle

¹Some machines were equipped with the French Le Rhône 9 rotary engine .

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  Replica of a Fokker Dr.I as it flew from Richthofen on its last mission, Deutsches Museum in Munich

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  Front view of a Dr.I replica

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  Fokker Dr.I

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  Fokker Dr.I, flown by Rittmeister Freiherr von Richthofen in April 1918

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  Fokker Dr.I from Lt. Ravens

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  Fokker Dr.I, Josef Jacobs (48 victories): the most successful pilot on this type of aircraft

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  Fokker Dr.I

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  Fokker Dr.I

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  Fokker Dr.I

See also

• List of aircraft types

literature

• Enzo Angelucci, Paolo Matricardi: The planes. From the beginning to the First World War . Falken-Verlag, Wiesbaden 1976, ISBN 3-8068-0391-9 , ( Falken manual in color ).
• Uwe W. Jack: Manfred von Richthofen, the triplane and the first fighter squadron. In: Fliegerrevue X , No. 74, pp. 22–37
• Uwe W. Jack: Fokker Dr.I - the technology. In: Fliegerrevue X , No. 74, pp. 38–45
• Karlheinz Kens, Hanns Müller: The aircraft of the First World War 1914–1918 . Heyne, Munich 1973, ISBN 3-453-00404-3 .
• Günter Kroschel, Helmut Stützer: The German military aircraft 1910–1918 . Lohse-Eissing, Wilhelmshaven 1977, ISBN 3-920602-18-8 .
• Imrie, Alex: The Fokker Triplane . Arms and Armor Press, 1992, ISBN 1-85409-118-2 .
• Kenneth Munson: Warplanes. Fighter and training aircraft 1914–1919 . 2nd revised edition. Orell Füssli Verlag, Zurich 1976, ISBN 3-280-00824-7 , ( Airplanes of the World in Colors ), pp. 24, 121–122.
• Heinz Nowarra: The Development of Airplanes 1914–1918 . Lehmanns, Munich 1959.
• Karl R. Pawlas: German aircraft. 1914-1918 . Pawlas, Nuremberg 1976, ISBN 3-88088-209-6 , ( Aviation Documents 20), pp. 63-65.
• AR Weyl: Fokker the Creative Years. Oxford 1965.

Web links

Commons : Fokker Dr.I  - album with pictures, videos and audio files

• http://www.fliehaben-museum.de/Fokker_DR_1.html ( Memento from June 30, 2013 in the Internet Archive )