Evolved from the Ae 04, the A18 was designed by
Antonin Vlasak and Antonin Husnik to a Czechoslovak
Army specification. Retaining the Walter-built
185hp BMW Ilia engine and armament of twin synchronised
7.92mm Vickers guns, the A18 also retained the mixed construction of the preceding fighter prototypes,
but dispensed with the overhung upper wing
ailerons in favour of ailerons inset flush with the wingtips,
and also adopted tandem interplane struts. The
A18 prototype was flown in March 1923, and a production
series of 20 aircraft was ordered. The standard A18
was to establish three national altitude records, and
the A18B and A18C were one-off high-speed examples
which participated in the 1923 and 1924 national air
races respectively.
