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Fokker M.2

Страна: Германия

Год: 1913

Fokker - Spinne / M.1 - 1911 - Германия<– –>Fokker - M.3 - 1913 - Германия

A.Weyl Fokker: The Creative Years (Putnam)

In 1913 the Prussian Army held a competition for military aeroplanes. The object was to find the best aircraft that could be easily and quickly assembled and dismantled in the field, and transported speedily from place to place by road. At that time the assembly of existing aircraft was usually a time-consuming process: much rigging, truing-up and test flying were needed before a machine could be operational. The worst offenders were the Taube monoplanes with their elaborate wing bracing; the biplanes were better, but still far from practical as operational military vehicles. None of the German military aeroplanes was robust enough to withstand the kind of road transport to which they would be subjected in the field.
   Germany had another reason for seeking a more practical military aeroplane than she then had. France had evolved the concept of the light, fast, tactical scout aeroplane, capable of being readily transported by road and being easily and quickly assembled and dismantled. In war, these single-seaters would operate from fields close to the fighting line, making short-range reconnaissance flights in place of or as an adjunct to the cavalry. This idea appealed to the more far-sighted German pilots but found no favour with the General Staff, who held that a fighting troop of cavalry was the most reliable means of tactical reconnaissance. In the opinion of the brass-hats the military value of aircraft was still problematical and the only function they might be able to perform was strategic observation.
   The terms of the competition stipulated that each aeroplane, dismantled and with spares, a tent and repair facilities, must be transported on a single trailer or lorry: the design of the vehicle was left to the competitor. Time limits of two hours for assembling the aeroplane and one hour for dismantling were imposed. A journey of 250 miles had to be made along prescribed roads, punctuated by flights and assembling-and-dismantling exercises. All had to be performed within a set time and under strict supervision. The winner would receive an order for ten aircraft at 45,000 marks apiece (£2,550 at pre-1914 values).
   If simplicity of structure and ease of assembly had been the sole criteria for assessing the quality of the aircraft, the Fokker Spider would have had a good chance of winning the competition. Fokker realized, however, that the Spider’s appearance and performance placed it at a disadvantage: he needed a faster aeroplane.
   One of the fastest aeroplanes at Johannisthal at that time was the Kuhlstein Torpedo monoplane, which had been designed by Max Court. The design was taken up by the Berlin carriage-building firm of Kuhlstein, who took Court into their employ. The Torpedo had an elegant fuselage of good streamline form, and its external bracing was kept to a minimum. The fuselage structure consisted of round wooden hoops with a number of stringers acting as longerons; its cross-section was polygonal, and a good aerodynamic entry was provided by a shapely spinner on the airscrew. Construction was of wood and, as Fokker learned, this type of fuselage was not too satisfactory: it was neither light nor simple, and was susceptible to deformation.
   Fokker wanted something better for his competition entry. He soon had an idea.
   Behind the building in which the Fokker Aeroplanbau was housed, Emile Jeannin had his workshops. Jeannin made extensive use of steel tubing with welded joints in the construction of his monoplanes; wood was used only for the wing spars and ribs and secondary components. His first monoplane was not successful: unstable, prone to stalling, and affording its observer little view, it was not acceptable to the Army. The Army saw merit in the durable steel-tube method of construction, however, and suggested to Jeannin that he might build a Taube-type monoplane embodying his steel structural methods. The resulting Jeannin Stahltaube proved to be one of the sturdiest of these stable monoplanes, and a few examples remained in service until 1915.
   In some mysterious way Fokker contrived to obtain one of Jeannin’s welded steel-tube fuselages. Reinhold Platz found it one morning in the workshop. When he asked Fokker where it had come from, Fokker mumbled something about someone in town having made it for him, and left it at that. Platz told him that he could weld up such a structure just as well. Fokker was non-committal.
   This Jeannin welded fuselage was made the basic structure of the streamlined fuselage of the Fokker M.2 monoplane. Wooden hoops fitted over the steel-tube structure bore numerous light wooden stringers to give the fuselage a circular cross-section; the covering was of fabric. The aluminium engine cowling had neat lines and faired smoothly into the fuselage contours. The cylinder heads of the 95-h.p. six-cylinder Mercedes engine remained exposed, but the two radiators were shaped to fit neatly into the streamlined shape of the fuselage. The pilot sat in the rear cockpit, but the observer was so close in front of him that intercommunication was not difficult.
   Four sockets were welded to the lower longerons to provide attachment points for the wing spars. The spars were of wood, partly spindled out and with piano-wire drag bracing. The ribs had wooden webs with elongated lightening holes; the aerofoil section was similar to that of the Nieuport monoplane. The wings were fabric covered; all structural members were wholly enclosed, the only protuberances being the four attachment points for the bracing and control cables. The wing tips were slightly rounded, and lateral control was by warping.
   In the tail unit the flexible bamboo tailplane/elevator surface of the Spiders was replaced by a conventional fixed surface and movable elevators. All the tail surfaces had welded steel-tube frames. The balanced rudder was wholly above the fuselage; there was no fin.
   The undercarriage was much the same as that of the Spiders and the M.l, and retained the primitive central rear skid. There was a true tail skid but it was a protective device, not a real part of the undercarriage. Another unsatisfactory feature of the earlier Fokkers repeated on the M.2 was the attachment of the lift-bracing cables to the undercarriage skids.
   No record of the M.2’s performance seems to have survived, but it must have been little slower than the Kuhlstein Torpedo which, with 100 h.p., is believed to have attained a speed of about 145 km./hr. (90 m.p.h.).
   Whether the M.2’s performance was good or not, Fokker did not depend on the aircraft alone and kept his ear to the ground. He always regarded good intelligence as indispensable to industrial success, and it was vital that he should know what his rivals were doing about the competition.
   The object of Fokker’s greatest interest was Franz Schneider, the technical director of the Luft-Verkehrs-Gesellschaft, better known as L.V.G. Schneider was a Swiss and a competent engineer. He had contributed to the design of the Nieuport monoplane of 1910, an aeroplane remarkable for its clean lines, its simple, robust construction, and good performance. In the following year a Nieuport monoplane with the first 100-h.p. nine-cylinder Gnome engine won the keenly contested military competition in France.
   After this success Schneider was approached by the L.V.G. and subsequently joined the German company as technical director. He produced a monoplane design generally similar to the successful Nieuports; it was about the fastest aircraft then flying in Germany, its only serious rival being the Kuhlstein Torpedo monoplane. Schneider’s L.V.G. monoplane did not find immediate favour with the Army, however: several of the best military pilots crashed while testing the type; it was said to lack stability; and its observer was even more badly placed than in the Taube.
   However, the monoplane that Schneider designed for the German competition had perhaps the best chance of winning. The L.V.G. machine, powered by a 70-h.p. Mercedes, was relatively small; it was robustly built; and it could be assembled and dismantled quickly. For the competition Schneider designed a special road-transport vehicle that could carry the monoplane’s fuselage with its tail unit and undercarriage assembled and in place; a retractable ramp facilitated loading and unloading of the fuselage. Under the fuselage supports were shelves for spares and tools, and there was space for repairs to be made. The wings formed the side walls of the vehicle and the whole was covered by a tarpaulin. Schneider applied for patents to cover several of the features of his vehicle.
   Fokker knew some of the L.V.G. mechanics, and he managed to learn all about Schneider’s preparations and the details of his ingenious transporter. Fokker’s transport vehicle resembled Schneider’s sufficiently closely for the L.V.G. designer to warn Fokker, before the competition, against infringement of his patents. Fokker did not heed the warning: the competition was not held in public and, as the patent law then stood, Schneider would not be able to prove infringement.
   Schneider’s monoplane had little to commend it as a military aircraft, but it was never put to the test. A daring and skilful Russian pilot, Elia Dunetz, had been engaged to fly the L.V.G. in the competition. On April 24, 1913, the monoplane’s wing broke up in flight; it crashed and Dunetz was killed.
   With his most dangerous rival eliminated, Fokker’s chances were considerably enhanced. When the competition began he raced his aircraft-laden vehicle over the prescribed route as quickly as he could. His team organization was excellent and gained him valuable time at the assembly and dismantling periods. He won the competition hands down.
   Yet it is doubtful whether Fokker really got the promised order for ten aeroplanes, for no record of the aircraft can be traced. Surviving military pilots of those early days are sure there were never as many as ten Fokker monoplanes of any 1913 type in Army service. It is also certain that no Fokker aircraft built in 1913 was ever scheduled for mobilization (all earlier Spiders supplied to the Army were training aircraft never intended for operational use).
   The answer may rest in the report on the M.2 made by Leutnant Muehlig-Hofmann. He had tested the aircraft at the request of the Doeberitz establishment, and found it to be directionally unstable, lacking adequate rudder control, and useless for military purposes.
   These criticisms may have been responsible for the modifications that were made to the M.2’s tail unit. The original divided elevator was replaced by a single long-chord surface, the single rudder by a two-piece unit disposed above and below the fuselage. Even after modification the M.2’s career was brief, and it participated in no other competition.

J.Herris Fokker Aircraft of WWI. Vol.1: Spinne - M.10 & Watercraft (A Centennial Perspective on Great War Airplanes 51)

Fokker M.2

  The M.2 was the next Fokker design. Also intended for the Army, it was an attempt to improve performance. The M.1 was sturdy but even Fokker realized that it was not fast. The contemporary Kuhlstein Torpedo had a good reputation as one of the fastest aircraft. Designed by Court and built by Kuhlstein, the aircraft had a streamlined fuselage of circular cross-section, but it was made totally of wood and was heavy.
  The Fokker M.2 featured a fuselage of circular cross-section, but the basic square structure, formed of four welded steel tube longerons, was faired into the circular cross-section with light stringers covered with fabric. The wings were made of fabric-covered wood spars and ribs while the tail surfaces were framed with welded steel tube covered with fabric.
  The M.2 was powered by a 100 hp Mercedes cooled by two radiators that were curved to fit the fuselage profile.
  Fokker entered his M.2 in an August Army competition that required the competitors to be trucked to the test site, assembled there, then flown. Fokker modified the tail surfaces several times to improve flight characteristics. Four examples, A.96-99/13, were ordered.
  Because a Rumpler Taube fatally crashed on 4 September, (for the first time), load tests were held at Doberitz with 13 aircraft. Fokker A.99/13 reached the highest factor, 4.5, and the military were duly impressed.
  This confirms that A96-99/13 were delivered.

Fokker M.2 Specifications
   Engine: 95 hp Mercedes or 100 hp Argus
   Wing: Span 13.20 m
   General: Length 8.50 m
   Max Speed: 100 km/h

J.Herris - Fokker Aircraft of WWI. Vol.1: Spinne - M.10 & Watercraft /Centennial Perspective/
The Fokker M.2 in its original form (Version 1) with divided elevator and single rudder surface.
The versions differed primarily by the outside of their tail surfaces in an attempt to improve flying qualities. (Peter M. Grosz collection/STDB)
J.Herris - Fokker Aircraft of WWI. Vol.1: Spinne - M.10 & Watercraft /Centennial Perspective/
Version 2 of the M.2. (Peter M. Grosz collection/STDB)
J.Herris - Fokker Aircraft of WWI. Vol.1: Spinne - M.10 & Watercraft /Centennial Perspective/
Version 3 of the M.2. (Peter M. Grosz collection/STDB)
J.Herris - Fokker Aircraft of WWI. Vol.1: Spinne - M.10 & Watercraft /Centennial Perspective/
Version 4 of the M2. (Peter M. Grosz collection/STDB)
J.Herris - Fokker Aircraft of WWI. Vol.1: Spinne - M.10 & Watercraft /Centennial Perspective/
Version 4 of the M.2. (Peter M. Grosz collection/STDB)
J.Herris - Fokker Aircraft of WWI. Vol.1: Spinne - M.10 & Watercraft /Centennial Perspective/
Tony Fokker in front of version 4 of the M.2. (Peter M. Grosz collection/STDB)
J.Herris - Fokker Aircraft of WWI. Vol.1: Spinne - M.10 & Watercraft /Centennial Perspective/
Version 4 of the M.2 in the 1913 military aircraft competition. Fokker is standing to the right of the airscrew, wearing a scarf.
J.Herris - Fokker Aircraft of WWI. Vol.1: Spinne - M.10 & Watercraft /Centennial Perspective/
The M.2 on its transportation Daimler truck as required by the competition. (Peter M. Grosz collection/STDB)
J.Herris - Fokker Aircraft of WWI. Vol.1: Spinne - M.10 & Watercraft /Centennial Perspective/
Version 4 of the M2. (Peter M. Grosz collection/STDB)
A.Weyl - Fokker: The Creative Years /Putnam/
Fokker M.2
J.Herris - Fokker Aircraft of WWI. Vol.1: Spinne - M.10 & Watercraft /Centennial Perspective/
Fokker M.2