Another variant of the D 1 developed in response to the C1 programme of 1923, the D 19 appeared in the summer of 1925 with a 400hp Hispano-Suiza 12Jb 12- cylinder water-cooled Vee-type engine. By comparison with the D 1, the D 19 had longer span, narrower chord ailerons and a wing spanning 12.50m with an area of 24.00m². Demonstrated in Switzerland in August 1925, the D 19 received a new wing of 25.00m² similar to that of the D 9 and D 12 before CEPA testing, in which performance proved mediocre owing to mismatching of the propeller. Three examples of a modified version of the D 19 were ordered by the Swiss government. Specified armament comprised two fuselage-mounted 7.7mm guns, the paired Lamblin radiators mounted on the undercarriage legs gave place to a Chausson frontal radiator and a wing similar to that of the D 1 was adopted. A second D 19 prototype was completed with these modifications, this being sold in 1928 to Belgium, and the first Swiss aircraft was ferried to the EKW (Eidg. Konstruktions-Werkstatte) in March 1926. The two other Swiss aircraft were transported to Switzerland in February 1927 for assembly by the EKW, subsequently entering service with the Fliegertruppe. The three D 19s participated in the 1927 Zurich-Diibendorf international aviation meeting, one being winner of the closed-circuit race for fighters with a speed of 250km/h. Used primarily for combat training by the Fliegertruppe, one D 19 was lost in 1930, and the remaining two continued in service until 1940.