Aero Ae.04

Successful testing of the Ae 02 led Vlasak and Husnik to revise the basic design in accordance with the requirements of the air component of the Czechoslovakian Army and to accept the BMW IlIa six-cylinder water-cooled engine rated at 185hp and for which a manufacturing licence had been acquired by Walter. Flown as the Ae 04 in 1921, the new prototype established a national altitude record of 6361m and was then displayed at the 2nd International Aircraft Exhibition in Prague. Retaining the structure and armament of the Ae 02, the Ae 04 transferred fuel tankage to the fuselage and initially flew with an automobile- style frontal radiator, this giving place to a chin-type radiator during flight development. Only one prototype of the Ae 04 was built, further development resulting in the A18.