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

Thulin FA

  According to a Royal Decree, dated September 22, 1917, funds were set aside for the purchase of four two-seat reconnaissance airplanes, to be powered by 160 h.p. Benz or Mercedes engines. The airplane was to be armed with one flexible machine gun, being fitted with radio gear and having the ability of operating both with wheels and on floats. Four days after the Royal Decree, the Sodertelge Verkstader SW 16 was destroyed in a fatal crash at Malmen, resulting in the SW 16 being out of the competition. Both AETA and NAB submitted offers, with the former being accepted.
  In the event, the available funds proved enough for seven airplanes, at the cost of 16,350 kronor each. A contract for the delivery of seven Thulin FA’s was signed on February 22, 1918, four of which were to be powered by Benz engines and the remainder with Mercedes engines. One of the conditions was that the Thulin FA would be able to operate on wheels, skis, as well as on floats. A highly unrealistic delivery schedule called for the first airplane to be delivered on May 17. The first Thulin FA, serial number 864, did not fly until August 5.
  A period of intense test flying commenced, with the airplane finally being delivered on September 8. On the same day, tragedy struck when the second Thulin FA (866) was destroyed in a fatal crash. The cause of the crash was due to the airplane entering a stall on take-off. The post-crash investigation put forward recommendations of increasing the wing’s angle of incidence, as well as fitting an additional front strut to the lower wings.
  Two additional Thulin FA’s (868 and 870) were delivered in October and September respectively. One Thulin FA was experimentally fitted with floats, but trials showed a distinct lack of performance, mostly due to the low output of the engine. The last three Thulin FA’s were delivered in January 1919 (872 and 874) and November 1919 (876) respectively.
  In service, it was quickly recognized that the Thulin FA was underpowered, resulting in poor overall performance. Additionally, it also proved to be unstable in flight. Nevertheless, the Thulin FA’s were flown quite intensely, with three accumulating 200 flight hours. Two were written off, on August 17, 1919 (872) and September 30, 1919 (868), the latter due to engine failure on take-off. The final three Thulin FA’s were struck off charge on December 5, 1921.
  An eighth Thulin FA, powered by a Thulin D inline engine, was exhibited in Copenhagen in April 1919. Two Thulin FA’s were sold to the Netherlands in November 1918. The ultimate fate of these three airplanes is unknown.

Thulin FA Technical Data and Performance Characteristics
   Engine: 1 x 150 h.p. Benz or 160 h.p. Mercedes
   Wingspan: 12,80 m
   Length: 7,20 m
   Height: 3,32 m
   Wing area: 44 m2
   Max take-off weight: 1,595 kg
   Empty weight: 1,095 kg
   Maximum Speed: 130 km/h
   Endurance: 6 hours