Prototype Wackett when fitted with a DH Gipsy Major engine. Performance poor so refitted with a Gipsy Six. Heavier engine improved performance but at expense of a higher stalling speed and longer take-off run. Warner Scarab radial selected for production model (CA-6). The delays meant the RAAF adopted the DH82 Tiger Moth as its main trainer. 200 CA-6s were delivered to the RAAF compared with 1085 DH82.