Twenty aircraft were built, including six prototypes and development aircraft. Screenshots of first GUIs of Apple Lisa prototypes show the early designs. In contrast to physical prototypes, which entail manufacturing time in the design. The design is inspired by Sports prototypes and racing cars. This same arrangement also included the manufacture of five Tiger prototypes. Testing the first prototypes began in 2008. SC3-Gs for later prototypes and production fighters. The aforementioned initial four prototypes (V1-V4) were built with the conventional gear configuration. Only three working prototypes of the Jackhammer were built. Dassault received a contract to build two prototypes. Two prototypes of the T28 were built. In 1936 testing began of three further "V3" prototypes, built in Porsche's Stuttgart shop. Beech built three airworthy full-scale prototypes. Bell agreed and set to work on producing three prototypes. Manufacture of the 10 Cheyenne prototypes was completed by 1969.