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Fokker D.VIIF

Description

The Fokker D.VII was designed by Reinhold Platz of the Fokker-Flugzeugwerke. His task was to create a fighter capable of beating the French SPAD XIII and British S.E.5a fighters. Some notable design features of the type included a metal airframe structure, a thick-sectioned wing, and a lack of bracing wires.

A competition among various new fighters took place in Adlershof from January 21st to February 12th, 1918, during the course of which the D.VII prototype proved to be the fastest, most durable, and the best-climbing aircraft. Manfred von Richthofen, a close friend of Anthony Fokker, also evaluated the prototype and noted some minor flaws. In particular, he noted the aircraft exhibited instability in a long dive, which was later corrected. The success of the design led to it being produced at a number of factories, including Fokker Flugzeugwerke, Albatros Werke, and the Ostdeutsche Albatros Werke. The Fokker D.VII would become one of the best - if not ultimately the best - fighter by the end of the war. In total, 2029 planes were produced and sent to the front by the end of 1918.

The first production aircraft reached the frontline airfields of Bavarian squadrons in April 1918. The Fokker D.VII was used to escort bombers, engage enemy fighters, and attack balloons; it was rarely used for strafing enemy supply columns in the immediate battle area and for recon. During its initial service, it became clear that the water-cooled radiator did not cool the engine sufficiently. The problem was fixed by modifying the radiator facing, engine cowling, and by increasing the airflow through the cylinders.

D.VII pilots noted the type’s good climb speed, excellent cockpit visibility, stability in manoeuvres, and good handling at low speeds. Pilots excitedly exclaimed, “The plane is like hanging on its propeller!” All of these attributes helped pilots in carrying out offensive and defensive missions. German squadrons equipped with this type were the main opponents of Allied aviation until the war’s end.

The Fokker D.VII was generally equipped with the Mercedes D.IIIa engine, but a new BMW engine type with the D.VIIF designation was also fitted. This new high compression BMW engine with high altitude control gave the D.VII much better performance. Its climb rate was almost twice that as the Mercedes-equipped version, and when flown at maximum throttle the engine was capable of generating almost 250 horsepower at ground level for a short time. With a nominal rating of 230 horsepower and a newly designed carburettor, this engine very much improved the aircraft’s high altitude performance and pushed the aircraft’s performance to a new level. However, there was a persistent shortage of BMW engines, and as a result, only every third or fourth aircraft had this type of engine installed.

This BMW IIIa engine had a special control lever - “Höhengashebel” - which was used to gain more power at higher altitudes. Engaging it at lower altitudes could lead to engine malfunction (detonation).

The D.VIIF was mainly supplied to the best and most proven frontline squadrons. As a result, the best German pilots were now able to outclass the latest Allied aircraft types in a plane superior to those of the Allies in almost every important aspect.

Engine
6 cyl. inline BMW IIIa 232 hp

Dimensions
Height: 2950 mm
Length: 6950 mm
Wing span: 8700 mm
Wing surface: 20,4 sq.m

Weight
Empty: 669,5 kg
Takeoff: 904 kg
Fuel capacity: 95 l
Oil capacity: 20,7 l

Maximum airspeed (IAS)
sea level — 197 km/h
1000 m — 192 km/h
2000 m — 184 km/h
3000 m — 181 km/h
4000 m — 176 km/h
5000 m — 165 km/h
6000 m — 153 km/h
7000 m — 140 km/h
8000 m — 126 km/h
9000 m — 106 km/h

Climb rate
1000 m — 2 min. 18 sec.
2000 m — 4 min. 40 sec.
3000 m — 7 min. 11 sec.
4000 m — 9 min. 47 sec.
5000 m — 12 min. 42 sec.
6000 m — 16 min. 23 sec.
7000 m — 21 min. 19 sec.
8000 m — 28 min. 59 sec.

Service ceiling ~9000 m

Endurance at 1000 m
nominal power (combat) - 1 h. 50 min.
minimal consumption (cruise) - 5 h. 30 min.

Armament
Forward firing: 2хLMG 08/15 Spandau 7,92mm, 500 rounds per barrel.

References
1) Fokker DVII No2009/18. Type C.1 captured and tested by French.
2) Essais de cellule de lavion Fokker Type D.VII.
3) Fokker D.VII Aces of World War I. Part1, 2 and 3 by Norman Franks and Greg VanWyngarden.
4) Fokker D.VII in action. By D. Edgar Brannon Aircraft Number 166.
5) Windsock Datafile Special - Fokker D.VII Anthology 1 & 2. Albatros Productions LTD., 1997.
6) Profile publications. The Fokker D.VII Number 25.
7) FLIGHT Magazine - A Fokker Biplane of recent type. 1918.
8) Technical description and operation manual for Bavarian engine type BMW IIIa 185hp. Bayerische Motoren Werke A.-G., München 1918.
9) NACA REPORT No.135. Performance of B.M.W. 185-horsepower airplane engine. By S.W.Sparrow. Bureau of Standards. 1919.
10) Report on the 230 H.P.Bayern Aero Engine. Air Ministry, Directorate of Research. May, 1919.

Modifications

Gunsight
Additional sight with front sight and rear sight mountings
Additional mass: 1 kg

Anemometer
Wilhelm Morell Anemometer (45-250 km/h)
Additional mass: 1 kg

Cockpit light
Cockpit illumination lamp for night sorties
Additional mass: 1 kg

High Altimeter
D.R.P Altimeter (0-8000 m)
Additional mass: 1 kg

Collimator Day
Oigee Reflector-type Collimator sight (daytime dimmer installed)
Additional mass: 2 kg

Thermometer
A.Schlegelmilch engine coolant temperature indicator (0-100 °C)
Additional mass: 1 kg

Collimator Night
Oigee Reflector-type Collimator sight (daytime dimmer removed)
Additional mass: 2 kg