FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1920
1920 - 0174.PDF
FEBRUARY 12, 1920 With regard to the performance of the Fokker DbI, it should bepointed out that this was not superior to that of the Fokker E IV, but on the other hand, the D I was very easy to land. " The Fokker type D II (Fig. 5) differs from the D I inthat it is fitted with a 100 h.p. Oberursel rotary engine. In this machine there was no fixed vertical fin, but otherwise thecontrol surfaces and main planes resembled those of the D I. The undercarriage differs somewhat from the normalone, as exemplified by the D I, inasmuch as it has three instead of two chassis struts on each side. The performanceis better than that of the Fokker D I, and is approximately the same as that of the E IV. " A development of the Jast two types is the FokkerD III which appeared about the middle of 1916 (Fig. 6). This machine represents a considerable improvement inperformance. The armament consists of two machine guns. It is on this type that Bolcke has had some of hisgreatest successes, especially in the neighbourhood of Verdun. The power plant was a 160 h.p. Oberursel, which representedthe highest power available at that date for an engine suitable type. The wing structure is braced by two lift and two anti- lift cables, and also by drift cables running to the upper ends of the front struts. These two cables also act to a certain extent as lift cables. The undercarriage construction re- sembles that of the Fokker D II with three struts on each side. The Fokker D V has a greater speed than its proto- types, and is also distinguished by a ' spinner ' over the propeller boss as well as by a stream-line cowling round the engine. Only a small space between the cowl and the spinner is left open for the entry of the air. A particular feature of the Fokker D V is its extraordinary manoeuvrability, which should render it very useful as a sporting machine. At the fighting schools the Fokker types D III to D V were employed right up to the end of the War. " Then followed a long period which was devoted to ex- periments, caused by the vast increase in the demand for performance and strength, which was very urgent at that time. " These experiments resulted in the construction of the Fokker Dr. I, shown in Fig. 9. This machine was very much MORE FOKKER MILESTONES : 9. The Dr. I (triplane). 10. The D VJr. 11 and 12. The D VII. 13 and 14 -••>:• « - . The D VIII . •_' or single-seater machines. The undercarriage of this type shows a return to the usual form. A feature of the wing bracing of the Fokker D II and D III machines is the pr6- vision of two external drift cables attached to the upper and lower ends of the front inner inter-plane struts. Although wing warping was the standard, some of the type D III Fokker machines were provided with ailerons. The reason for doing away with wing warping in favo'ur of ailerons is chiefly that the breakage of a cable not only weakens the wing bracing, but actually renders the machine uncontrollable. Also the ever-increasing demands for strength and rigidity could not be provided in wings of the warping type. " The Fokker type D IV, shown in Fig. 7, is the first single- seater in Germany to employ the 160 h.p. Mercedes engine, which type held a leading place in single-seater fighters for a long time. The Fokker D IV has a greater climb than any of the previous machines. Lateral control is by means of ailerons of the balanced type. " In October, 1916, the Fokker D V shown in Fig. 8, made its appearance. As distinct from previous Fokker single- seater biplanes, the D V has only one pair of struts on each side. The wings are staggered and have a certain amount of sweep-back. The ailerons are balanced as in the previous feared by the enemy, and was to be found at the front up to the summer of 1918. The Fokker Dr. I represented an increase in speed, climb and manoeuvrability not hitherto attained. This machine represented a leap forward compared with any previous ones. Rittmeister Frhr. Von Richthofen and his squadron have, as is well known, had enormous successes with the Fokker triplanes. Typical of this machine is the employment of cantilever wings of which only the top plane is fitted with ailerons. " Only the centre section is braced with diagonal cables. In addition the three planes are connected by a narrow strut on each side. It is worthy of note that the machine is quite capable of flying without these struts, and that the first specimens which arrived at the front were, in fact, without them. Remarkable is also the employment bf a large fixed tail plane and the fitting of a fourth plane in the form of a wing-sectioned casing round the wheel axle. The power plant of these very light machines is a no h.p. Oberursel engine. " A step between the Fokker triplanes and the Fokker D VII, which followed later, is formed by the Fokker D VI, shown in Fig. 10. As in the triplane, this machine has a fixed tail plane, but no vertical fin in front of the rudder. A 174
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
