Sensing demand for the type, de Havilland continued to modify the Rapide's design following its entry to service, creating both refinements and entirely new derivatives as a result. Aiming to produce a faster version of the Rapide, a smaller, lighter and externally cleaner version, designated as the DH.90 Dragonfly, emerged; first flying in August 1935, the DH.90 failed to achieve a similar rate of sales to the Rapide and production was terminated in 1938 after 67 aircraft had been completed. In November 1935, the 60th airframe to be produced, "G-ADWZ", was modified and used by de Havilland as a trials aircraft. Fitted with elongated rear windows, cabin heating, thickened wing tips, and a strengthened airframe to allow for an elevated gross weight of , G-ADWZ later participated in trials at Martlesham Heath, after which the higher gross weight was cleared for service.