The A.18 was designed by Antonin Vlasák and Antonin Husnik and first flew in March 1923; only one of three prototype fighters that Aero flew that year, but this one was selected for production over the A.19 and A.20 that competed with it.[3]
The A.18B and A.18C were specially modified racing variants that competed in the Czech Aero Club's first two annual air races, in 1923 and 1924 respectively. Both aircraft won their races, and the A.18C is preserved at the Prague Aviation Museum in Kbely along with a replica of a standard A.18 fighter.[3]