Dewoitine D 27
|FIGHTER||Virtual Aircraft Museum / France / Dewoitine|
The design that took Emile Dewoitine's parasol fighter formula to the apex of its development was the D 27, which was evolved to meet the requirements of the STAe 1926 C1 leger programme for lightweight fighters. Adhering closely to the structural concept of preceding fighters, but embodying much aerodynamic refinement and a split-axle (with independently articulated wheels) rather than cross-axle undercarriage, the D 27 was powered by the 500hp Hispano-Suiza 12Mb (HS 57) 12-cylinder Vee engine and had an armament of two synchronised 7.7mm guns. The liquidation of the Construction Aeronautique E Dewoitine in January 1927 resulted in the transfer of development of the D 27 to the EKW in Switzerland, where a prototype flew on 3 June 1928. By the end of the year, three had been ordered by Romania, one by Argentina and three by Yugoslavia (of which two were to be delivered as assemblies for completion by Zmaj at Zemun), and the prototype was undergoing evaluation by the Swiss Fliegertruppe in competition with Alfred Comte's AC-1. In the autumn of 1928, the EKW initiated a pre-series of 12 D 27 fighters, these adopting a redesigned tail and a revised wing of 0.45m2 less area, modifications first tested in the Laboratoire Eiffel wind tunnel. Meanwhile, in March 1928, Emile Dewoitine had reestablished himself in France, forming the Societe Aeronautique Francaise-Avions Dewoitine. The second and third pre-series D 27s were delivered to France in April 1929, the former being re-engined with the 400hp HS 12Jb as the D 272 for aerobatic demonstrations, and the latter undergoing STAe evaluation at Villacoublay from 28 May equipped with two 7.7mm Darne guns. On 29 November 1929, a contract was issued by France's DGT (Direction Generale Technique) of the Ministere de l'Air for the second and third pre-series aircraft plus three (later increased to four) additional fighters to be assembled by Liore-et-Olivier. The D 27 was offered to the Forces Aeriennes Terrestres as the D 271 with the 500hp HS 12Hb engine and as the D 273 with a Gnome-Rhone Jupiter VII with a compressor enabling 425hp to be delivered at 4000m, but neither model was adopted. At the end of 1929, however, the decision was taken in principle to re-equip the fighter element of the Swiss Fliegertruppe with the D 27, a pre-series of five being ordered from the EKW as D 27 Ills, with deliveries commencing in 1931. A pre-production batch of 15 followed, additional contracts being placed for 45 D 27 Ills to bring deliveries to the Fliegertruppe to 66 (including the prototype). These remained first-line fighter equipment until 1940, when they were relegated to tuitional tasks, being finally scrapped in 1944.