The registration VH-CYB was never formally taken up. It was a step in the transition of the CA-6 Wackett into the Yeoman YA-1 Cropmaster. Wackett VH-AIV served as the basis of this test aircraft. It was fitted with the metal tail designed for the Cropmaster but retained the Warner Scarab radial of the wartime trainer. -CYB was completely rebuilt in early 1962 as a production YA-1 Cropmaster (c/n 106) with a Lycoming O-540 engine. A new registration, VH-CYW, was allocated.