Dewoitine D.27 / D.272 / D.275
The D 27 was evolved to meet the requirements of the STAe 1926 C1 leger programme for lightweight fighters.
Incorporating a split-axle (with independently articulated wheels) rather than cross-axle undercarriage, the D 27 was powered by the SLM-Saurer-built 500hp Hispano-Suiza 12Mb (HS 57) 12-cylinder Vee engine and had an armament of two synchronised 7.7mm guns. The fuel was carried in a tank which formed the underside of the centre fuselage. In emergency this tank could be jettisoned.
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 1929, three had been ordered by Romania, one by Argentina and three by Yugoslavia (of which two were to be assembled by Zmaj at Zemun), and the prototype was undergoing evaluation by the Swiss Fliegertruppe in competition with Alfred Comte's AC-1.
The five prototypes and two of a strengthened model, the D 53, were flown experimentally for a time on board the aircraft carrier Bearn.
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 0.45sq.m 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 IIIs, with deliveries commencing in 1931. A pre-production batch of 15 followed, additional contracts being placed for 45 D 27 IIIs to bring deliveries to the Fliegertruppe to 66 (including the prototype). Sixty-six were delivered from 1930 to the Swiss Fliegertruppe, which also received 11 examples of the D 26, a version fitted with a 250-hp Wright Cyclone radial engine. Fifty-six of the Swiss D 27s were still in first-line fighter squadron service when war broke out in 1939. During the following year, they were withdrawn to training units, from which they did not disappear completely for another decade.
On November 30, 1930, Dewoitine chief test pilot Doret broke the world 1000 km (621 mile) closed-circuit speed record flying a Dewoitine D 27 at an average of 286.227 km/h (177.854 mph).
Swiss D 27 III
Take-off weight: 1415 kg / 3120 lb
Empty weight: 1038 kg / 2288 lb
Wingspan: 10.30 m / 33 ft 10 in
Length: 6.56 m / 21 ft 6 in
Height: 2.78 m / 9 ft 1 in
Wing area: 17.55 sq.m / 188.91 sq ft
Max. speed: 298 km/h / 185 mph
Range: 425 km / 264 miles
Armament: 2 x 7.5-mm (0.295-in) machine-guns
Service ceiling: 8300 m / 27231 ft
Climb to service ceiling: 11 minutes