J.Forsgren Swedish Military Aircraft 1911-1926 (A Centennial Perspective on Great War Airplanes 68)

FVM S 18

  The first indigenous design of FVM was the large two-seat S 18 reconnaisance biplane. The S was short for Spaningsflygplan (ie reconnaissance airplane), with 18 indicating the year 1918. Designed by Henry Kjellson, a total of 15 S 18’s were eventually built. It appears likely that Kjellson’s main source of inspiration was the Thulin FA, as well as various contemporary German airplanes.
  An initial contract for four airplanes, referred to as ’’Albatros 260 h.p.”, was signed on September 9, 1918, with an additional six being ordered in February 1919. The first S 18, serial number 980, was flown for the first time on 20 March 1919. The following month, this airplane was statically displayed at the Skandinavian Aero Exhibition in Copenhagen. After the completion of the ten S 18’s, an additional five airplanes were built. With funds not yet being allocated, these were referred to as spare fuselages and wings. Nevertheless, as the mobilization called for a total of 15 S 18’s, these were eventually completed. The last S 18 was delivered in August 1920. Many of the 260 h.p. Mercedes engines came from the batch of AEG G.V’s imported in 1919. However, the first and last production S 18’s were fitted with 260 h.p. Maybach engines.
  The S 18 was AFK’s main reconnaissance airplane during the early 1920s. Many long distance flights were made, with one pilot, Axel Ljungdahl, managing to stay aloft for 14 hours. One S 18 was experimentally fitted with twin floats, but protracted tests showed the airplane being wholly unsuitable in the maritime reconnaissance role.
  In 1923, one S 18, serial number 0112, was leased to Hugo Montgomery and registered as S-ALAA for participation in the ILUG arrival contest. Tragically, the heavily loaded airplane spun in prior to landing at Rotterdam, the Netherlands, on August 1, 1923, killing all three aboard.
  The last two S 18’s, serial numbers 998 and 0108, were struck off charge in April 1926.
  One trainee pilot later wrote: ’’For reasons of range, the wing area of the S 18 was overwhelmingly huge. It is of course something of an exaggeration to say that if one wingtip scraped the brick tower (at Malmen), the other scraped the barracks on the other side of the field. At first glance, one had that kind of vision, or something like that. The machine was huge and heavy.
  For some darned inexplicable reason, the control column was so short that it barely reached one’s knees. Superhuman armstrength, often combined with similarly strong legs, proved necessary to maneouver the colossous. In other words, it was not popular. At least among us student pilots, who did not have any aspirations of achieving long distance records.”

FVM S 18 Technical Data and Performance Characteristics
   Engine: 1 x 260 h.p. Mercedes
   Length: 8,70 m
   Wingspan: 14,00 m
   Height: 3,42 m
   Wing area: 45 m2
   Empty weight: 1,250 kg
   Maximum weight: 1,850 kg
   Maximum speed: 156 km/h
   Armament: 1x8 mm m/22 machine gun